diff --git a/PowerEditor/src/Notepad_plus.cpp b/PowerEditor/src/Notepad_plus.cpp
index 67a7e60d..5d01fd03 100644
--- a/PowerEditor/src/Notepad_plus.cpp
+++ b/PowerEditor/src/Notepad_plus.cpp
@@ -4615,10 +4615,22 @@ void Notepad_plus::loadCommandlineParams(const TCHAR * commandLine, CmdLineParam
 	if (!commandLine || ! pCmdParams)
 		return;
 
+	NppParameters *nppParams = NppParameters::getInstance();
 	FileNameStringSplitter fnss(commandLine);
 	const TCHAR *pFn = NULL;
 
- 	LangType lt = pCmdParams->_langType;//LangType(pCopyData->dwData & LASTBYTEMASK);
+	// loading file as session file is allowed only when there is only one file
+	if (pCmdParams->_isSessionFile && fnss.size() == 1) 
+	{
+		Session session2Load;
+		if ((NppParameters::getInstance())->loadSession(session2Load, fnss.getFileName(0)))
+		{
+			loadSession(session2Load);
+		}
+		return;
+	}
+
+ 	LangType lt = pCmdParams->_langType;
 	int ln =  pCmdParams->_line2go;
     int cn = pCmdParams->_column2go;
 
@@ -4634,7 +4646,7 @@ void Notepad_plus::loadCommandlineParams(const TCHAR * commandLine, CmdLineParam
 
 		lastOpened = bufID;
 
-		if (lt != L_EXTERNAL && lt < NppParameters::getInstance()->L_END)
+		if (lt != L_EXTERNAL && lt < nppParams->L_END)
 		{
 			Buffer * pBuf = MainFileManager->getBufferByID(bufID);
 			pBuf->setLangType(lt);
diff --git a/PowerEditor/src/Notepad_plus_Window.cpp b/PowerEditor/src/Notepad_plus_Window.cpp
index e5289924..889a0647 100644
--- a/PowerEditor/src/Notepad_plus_Window.cpp
+++ b/PowerEditor/src/Notepad_plus_Window.cpp
@@ -94,7 +94,6 @@ void Notepad_plus_Window::init(HINSTANCE hInst, HWND parent, const TCHAR *cmdLin
 	if (cmdLineParams->isPointValid())
 		::MoveWindow(_hSelf, cmdLineParams->_point.x, cmdLineParams->_point.y, nppGUI._appPos.right, nppGUI._appPos.bottom, TRUE);
 	else
-		//::MoveWindow(_hSelf, newUpperLeft.x, newUpperLeft.y, nppGUI._appPos.right, nppGUI._appPos.bottom, TRUE);
 	{
 		WINDOWPLACEMENT posInfo;
 
diff --git a/PowerEditor/src/NppIO.cpp b/PowerEditor/src/NppIO.cpp
index a98ac20b..be0f096b 100644
--- a/PowerEditor/src/NppIO.cpp
+++ b/PowerEditor/src/NppIO.cpp
@@ -61,7 +61,7 @@ BufferID Notepad_plus::doOpen(const TCHAR *fileName, bool isReadOnly, int encodi
 	if (test != BUFFER_INVALID)
 	{
 		//switchToFile(test);
-		//Dont switch, not responsibility of doOpen, but of caller
+		//Don't switch, not responsibility of doOpen, but of caller
 		if (_pTrayIco)
 		{
 			if (_pTrayIco->isInTray())
@@ -1228,18 +1228,31 @@ bool Notepad_plus::fileLoadSession(const TCHAR *fn)
 			sessionFileName = fn;
 	}
 	
+	NppParameters *pNppParam = NppParameters::getInstance();
+	const NppGUI & nppGUI = pNppParam->getNppGUI();
 	if (sessionFileName)
 	{
-		bool isAllSuccessful = true;
-		Session session2Load;
-
-		if ((NppParameters::getInstance())->loadSession(session2Load, sessionFileName))
+		if ((nppGUI._multiInstSetting == multiInstOnSession || nppGUI._multiInstSetting == multiInst))
 		{
-			isAllSuccessful = loadSession(session2Load);
-			result = true;
+			TCHAR nppFullPath[MAX_PATH];
+			::GetModuleFileName(NULL, nppFullPath, MAX_PATH);
+			generic_string args = TEXT("-multiInst -nosession -openSession ");
+			args += sessionFileName;
+			::ShellExecute(_pPublicInterface->getHSelf(), TEXT("open"), nppFullPath, args.c_str(), TEXT("."), SW_SHOW);
+		}
+		else
+		{
+			bool isAllSuccessful = true;
+			Session session2Load;
+
+			if ((NppParameters::getInstance())->loadSession(session2Load, sessionFileName))
+			{
+				isAllSuccessful = loadSession(session2Load);
+				result = true;
+			}
+			if (!isAllSuccessful)
+				(NppParameters::getInstance())->writeSession(session2Load, sessionFileName);
 		}
-		if (!isAllSuccessful)
-			(NppParameters::getInstance())->writeSession(session2Load, sessionFileName);
 	}
 	return result;
 }
diff --git a/PowerEditor/src/Parameters.cpp b/PowerEditor/src/Parameters.cpp
index 3e3c8dbb..015e8c63 100644
--- a/PowerEditor/src/Parameters.cpp
+++ b/PowerEditor/src/Parameters.cpp
@@ -623,14 +623,14 @@ winVer getWindowsVersion()
 NppParameters * NppParameters::_pSelf = new NppParameters;
 int FileDialog::_dialogFileBoxId = (NppParameters::getInstance())->getWinVersion() < WV_W2K?edt1:cmb13;
 
-NppParameters::NppParameters() : _pXmlDoc(NULL),_pXmlUserDoc(NULL), _pXmlUserStylerDoc(NULL),\
-								_pXmlUserLangDoc(NULL), _pXmlNativeLangDocA(NULL),\
-								_nbLang(0), _pXmlToolIconsDoc(NULL),\
-								_nbRecentFile(0), _nbMaxRecentFile(10), _recentFileCustomLength(RECENTFILES_SHOWFULLPATH),_putRecentFileInSubMenu(false),
-								_pXmlShortcutDoc(NULL), _pXmlContextMenuDocA(NULL), _pXmlSessionDoc(NULL), _pXmlBlacklistDoc(NULL),\
-								_nbUserLang(0), _nbExternalLang(0), _hUser32(NULL), _hUXTheme(NULL),\
-								_transparentFuncAddr(NULL), _enableThemeDialogTextureFuncAddr(NULL), _pNativeLangSpeaker(NULL),\
-								_isTaskListRBUTTONUP_Active(false), _fileSaveDlgFilterIndex(-1), _asNotepadStyle(false), _isFindReplacing(false)
+NppParameters::NppParameters() :	_pXmlDoc(NULL),_pXmlUserDoc(NULL), _pXmlUserStylerDoc(NULL),_pXmlUserLangDoc(NULL),\
+									_pXmlNativeLangDocA(NULL), _nbLang(0), _pXmlToolIconsDoc(NULL), _nbRecentFile(0),\
+									_nbMaxRecentFile(10), _recentFileCustomLength(RECENTFILES_SHOWFULLPATH),\
+									_putRecentFileInSubMenu(false),	_pXmlShortcutDoc(NULL), _pXmlContextMenuDocA(NULL),\
+									_pXmlSessionDoc(NULL), _pXmlBlacklistDoc(NULL),	_nbUserLang(0), _nbExternalLang(0),\
+									_hUser32(NULL), _hUXTheme(NULL), _transparentFuncAddr(NULL), _enableThemeDialogTextureFuncAddr(NULL),\
+									_pNativeLangSpeaker(NULL), _isTaskListRBUTTONUP_Active(false), _fileSaveDlgFilterIndex(-1),\
+									_asNotepadStyle(false), _isFindReplacing(false)/*, _forceLoadingSession(false)*/
 {
 	// init import UDL array
 	_nbImportedULD = 0;
@@ -3901,6 +3901,14 @@ void NppParameters::feedGUIParameters(TiXmlNode *node)
 			else
 				_nppGUI._delimiterSelectionOnEntireDocument = false;
 		}
+        else if (!lstrcmp(nm, TEXT("multiInst")))
+		{
+			int val = 0;
+			element->Attribute(TEXT("setting"), &val);
+			if (val < 0 || val > 2)
+				val = 0;
+			_nppGUI._multiInstSetting = (MultiInstSetting)val;
+		}
 	}
 }
 
@@ -4236,6 +4244,7 @@ bool NppParameters::writeGUIParams()
 	bool titleBarExist = false;
 	bool stylerThemeExist = false;
 	bool delimiterSelectionExist = false;
+	bool multiInstExist = false;
 
 	TiXmlNode *dockingParamNode = NULL;
 
@@ -4610,6 +4619,11 @@ bool NppParameters::writeGUIParams()
 				element->SetAttribute(TEXT("delimiterSelectionOnEntireDocument"), TEXT("no"));
 			delimiterSelectionExist = true;
 		}
+		else if (!lstrcmp(nm, TEXT("multiInst")))
+		{
+			multiInstExist = true;
+			element->SetAttribute(TEXT("setting"), _nppGUI._multiInstSetting);
+		}
 	}
 
 	if (!noUpdateExist)
@@ -4817,6 +4831,12 @@ bool NppParameters::writeGUIParams()
 		GUIConfigElement->SetAttribute(TEXT("rightmostDelimiter"), _nppGUI._rightmostDelimiter);
 		GUIConfigElement->SetAttribute(TEXT("delimiterSelectionOnEntireDocument"), _nppGUI._delimiterSelectionOnEntireDocument);
 	}
+	if (!multiInstExist)
+	{
+		TiXmlElement *GUIConfigElement = (GUIRoot->InsertEndChild(TiXmlElement(TEXT("GUIConfig"))))->ToElement();
+		GUIConfigElement->SetAttribute(TEXT("name"), TEXT("multiInst"));
+		GUIConfigElement->SetAttribute(TEXT("setting"), _nppGUI._multiInstSetting);
+	}
 
 	insertDockingParamNode(GUIRoot);
 	return true;
diff --git a/PowerEditor/src/Parameters.h b/PowerEditor/src/Parameters.h
index 69cbcd23..315762af 100644
--- a/PowerEditor/src/Parameters.h
+++ b/PowerEditor/src/Parameters.h
@@ -97,6 +97,7 @@ enum UniMode {uni8Bit=0, uniUTF8=1, uni16BE=2, uni16LE=3, uniCookie=4, uni7Bit=5
 enum ChangeDetect {cdDisabled=0, cdEnabled=1, cdAutoUpdate=2, cdGo2end=3, cdAutoUpdateGo2end=4};
 enum BackupFeature {bak_none = 0, bak_simple = 1, bak_verbose = 2};
 enum OpenSaveDirSetting {dir_followCurrent = 0, dir_last = 1, dir_userDef = 2};
+enum MultiInstSetting {monoInst = 0, multiInstOnSession = 1, multiInst = 2};
 
 const int LANG_INDEX_INSTR = 0;
 const int LANG_INDEX_INSTR2 = 1;
@@ -181,6 +182,7 @@ struct CmdLineParams {
 	bool isPointValid() {
 		return _isPointXValid && _isPointYValid;
 	};
+	bool _isSessionFile;
 
 	LangType _langType;
 	CmdLineParams() : _isNoPlugin(false), _isReadOnly(false), _isNoSession(false), _isNoTab(false),_showLoadingTime(false),\
@@ -682,7 +684,7 @@ struct NppGUI
 			   _doTaskList(true), _maitainIndent(true), _openSaveDir(dir_followCurrent), _styleMRU(true), _styleURL(0),\
 			   _autocStatus(autoc_none), _autocFromLen(1), _funcParams(false), _definedSessionExt(TEXT("")),\
 			   _doesExistUpdater(false), _caretBlinkRate(250), _caretWidth(1), _enableMultiSelection(false), _shortTitlebar(false), _themeName(TEXT("")), _isLangMenuCompact(false),
-			   _smartHiliteCaseSensitive(false), _leftmostDelimiter('('), _rightmostDelimiter(')'), _delimiterSelectionOnEntireDocument(false) {
+			   _smartHiliteCaseSensitive(false), _leftmostDelimiter('('), _rightmostDelimiter(')'), _delimiterSelectionOnEntireDocument(false), _multiInstSetting(monoInst) {
 		_appPos.left = 0;
 		_appPos.top = 0;
 		_appPos.right = 700;
@@ -778,6 +780,7 @@ struct NppGUI
 	TCHAR _defaultDir[MAX_PATH];
 	TCHAR _defaultDirExp[MAX_PATH];	//expanded environment variables
 	generic_string _themeName;
+	MultiInstSetting _multiInstSetting;
 };
 
 struct ScintillaViewParams
diff --git a/PowerEditor/src/WinControls/Preference/preference.rc b/PowerEditor/src/WinControls/Preference/preference.rc
index ff0e38a3..ad015bd8 100644
--- a/PowerEditor/src/WinControls/Preference/preference.rc
+++ b/PowerEditor/src/WinControls/Preference/preference.rc
@@ -317,3 +317,13 @@ BEGIN
                     "Button",BS_AUTOCHECKBOX | WS_TABSTOP,91,103,160,10
 END
 
+IDD_PREFERENCE_MULTIINSTANCE_BOX DIALOGEX 0, 0, 455, 185
+STYLE DS_SETFONT | DS_FIXEDSYS | DS_CONTROL | WS_CHILD
+FONT 8, "MS Shell Dlg", 0, 0, 0x1
+BEGIN
+    GROUPBOX        "Multi-instance settings",IDC_MULTIINST_GB_STATIC,89,44,268,89,BS_CENTER
+    CONTROL         "Open session in a new instance of Notepad++",IDC_SESSIONININST_RADIO,
+                    "Button",BS_AUTORADIOBUTTON,123,68,226,10
+    CONTROL         "Always in multi-instance mode",IDC_MULTIINST_RADIO,"Button",BS_AUTORADIOBUTTON,123,87,218,10
+    CONTROL         "Default (mono-instance)",IDC_MONOINST_RADIO,"Button",BS_AUTORADIOBUTTON,123,106,196,10
+END
diff --git a/PowerEditor/src/WinControls/Preference/preferenceDlg.cpp b/PowerEditor/src/WinControls/Preference/preferenceDlg.cpp
index 55cd62d6..6f5f7cb4 100644
--- a/PowerEditor/src/WinControls/Preference/preferenceDlg.cpp
+++ b/PowerEditor/src/WinControls/Preference/preferenceDlg.cpp
@@ -96,9 +96,6 @@ BOOL CALLBACK PreferenceDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM lPa
 	{
 		case WM_INITDIALOG :
 		{
-			//_ctrlTab.init(_hInst, _hSelf, false, true, true);
-			//_ctrlTab.setFont(TEXT("Tahoma"), 13);
-			
 			_barsDlg.init(_hInst, _hSelf);
 			_barsDlg.create(IDD_PREFERENCE_BAR_BOX, false, false);
 			_barsDlg.display();
@@ -136,6 +133,9 @@ BOOL CALLBACK PreferenceDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM lPa
 			_autoCompletionDlg.init(_hInst, _hSelf);
 			_autoCompletionDlg.create(IDD_PREFERENCE_AUTOCOMPLETION_BOX, false, false);
 
+			_multiInstDlg.init(_hInst, _hSelf);
+			_multiInstDlg.create(IDD_PREFERENCE_MULTIINSTANCE_BOX, false, false);
+
 			_wVector.push_back(DlgInfo(&_barsDlg, TEXT("General"), TEXT("Global")));
 			_wVector.push_back(DlgInfo(&_marginsDlg, TEXT("Editing"), TEXT("Scintillas")));
 			_wVector.push_back(DlgInfo(&_defaultNewDocDlg, TEXT("New Document"), TEXT("NewDoc")));
@@ -147,14 +147,13 @@ BOOL CALLBACK PreferenceDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM lPa
 			_wVector.push_back(DlgInfo(&_printSettingsDlg, TEXT("Print"), TEXT("Print")));
 			_wVector.push_back(DlgInfo(&_backupDlg, TEXT("Backup"), TEXT("Backup")));
 			_wVector.push_back(DlgInfo(&_autoCompletionDlg, TEXT("Auto-Completion"), TEXT("AutoCompletion")));
+			_wVector.push_back(DlgInfo(&_multiInstDlg, TEXT("Multi-Instance"), TEXT("MultiInstance")));
 			_wVector.push_back(DlgInfo(&_settingsDlg, TEXT("MISC."), TEXT("MISC")));
-			//_ctrlTab.createTabs(_wVector);
-			//_ctrlTab.display();
+
 
 			makeCategoryList();
 			RECT rc;
 			getClientRect(rc);
-			//_ctrlTab.reSizeTo(rc);
 			rc.top += 10;
 			rc.bottom -= 50;
 			rc.left += 150;
@@ -171,29 +170,17 @@ BOOL CALLBACK PreferenceDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM lPa
 			_printSettingsDlg.reSizeTo(rc);
 			_backupDlg.reSizeTo(rc);
 			_autoCompletionDlg.reSizeTo(rc);
+			_multiInstDlg.reSizeTo(rc);
 
 			NppParameters *pNppParam = NppParameters::getInstance();
 			ETDTProc enableDlgTheme = (ETDTProc)pNppParam->getEnableThemeDlgTexture();
 			if (enableDlgTheme)
 				enableDlgTheme(_hSelf, ETDT_ENABLETAB);
+
 			return TRUE;
 		}
-/*
-		case WM_NOTIFY :		  
-		{
-			NMHDR *nmhdr = (NMHDR *)lParam;
-			if (nmhdr->code == TCN_SELCHANGE)
-			{
-				if (nmhdr->hwndFrom == _ctrlTab.getHSelf())
-				{
-					_ctrlTab.clickedUpdate();
-					return TRUE;
-				}
-			}
-			break;
-		}
-*/
-		case WM_COMMAND : 
+
+		case WM_COMMAND :
 		{
 			if (LOWORD(wParam) == IDC_LIST_DLGTITLE)
 			{
@@ -202,7 +189,6 @@ BOOL CALLBACK PreferenceDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM lPa
 					int i = ::SendDlgItemMessage(_hSelf, IDC_LIST_DLGTITLE, LB_GETCURSEL, 0, 0);
 					if (i != LB_ERR)
 					{
-						//printInt(i);
 						showDialogByIndex(i);
 					}
 				}
@@ -232,8 +218,15 @@ void PreferenceDlg::makeCategoryList()
 	{
 		::SendDlgItemMessage(_hSelf, IDC_LIST_DLGTITLE, LB_ADDSTRING, 0, (LPARAM)_wVector[i]._name.c_str());
 	}
+	setListSelection(0);
+}
 
-	::SendDlgItemMessage(_hSelf, IDC_LIST_DLGTITLE, LB_SETSEL, (WPARAM)TRUE, 0);
+void PreferenceDlg::setListSelection(size_t currentSel) const
+{
+	// Stupid LB API doesn't allow LB_SETSEL to be used on single select listbox, so we do it in a hard way
+	TCHAR selStr[256];
+	::SendDlgItemMessage(_hSelf, IDC_LIST_DLGTITLE, LB_GETTEXT, currentSel, (LPARAM)selStr);
+	::SendDlgItemMessage(_hSelf, IDC_LIST_DLGTITLE, LB_SELECTSTRING, currentSel, (LPARAM)selStr);
 }
 
 bool PreferenceDlg::renameDialogTitle(const TCHAR *internalName, const TCHAR *newName)
@@ -279,6 +272,23 @@ void PreferenceDlg::showDialogByIndex(int index)
 	_wVector[index]._dlg->display(true);
 }
 
+void PreferenceDlg::destroy()
+{
+	_barsDlg.destroy();
+	_marginsDlg.destroy();
+	_settingsDlg.destroy();
+	_fileAssocDlg.destroy();
+	_langMenuDlg.destroy();
+	_tabSettings.destroy();
+	_printSettingsDlg.destroy();
+	_defaultNewDocDlg.destroy();
+	_defaultDirectoryDlg.destroy();
+	_recentFilesHistoryDlg.destroy();
+	_backupDlg.destroy();
+	_autoCompletionDlg.destroy();
+	_multiInstDlg.destroy();
+}
+
 BOOL CALLBACK BarsDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM)
 {
 	NppParameters *pNppParam = NppParameters::getInstance();
@@ -937,7 +947,6 @@ BOOL CALLBACK SettingsDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM)
 					return TRUE;
 
 				case IDC_CHECK_REMEMBERSESSION:
-					//::SendMessage(_hParent, WM_COMMAND, IDM_SETTING_REMEMBER_LAST_SESSION, 0);
 					nppGUI._rememberLastSession = isCheckedOrNot(wParam);
 					return TRUE;
 
@@ -1463,27 +1472,12 @@ BOOL CALLBACK LangMenuDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM lPara
 	{
 		case WM_INITDIALOG :
 		{
-			/*
-			::SetDlgItemInt(_hSelf, IDC_TABSIZEVAL_STATIC, nppGUI._tabSize, FALSE);
-
-            _tabSizeVal.init(_hInst, _hSelf);
-			_tabSizeVal.create(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_STATIC), IDC_TABSIZEVAL_STATIC);
-			::SendDlgItemMessage(_hSelf, IDC_CHECK_REPLACEBYSPACE, BM_SETCHECK, nppGUI._tabReplacedBySpace, 0);
-			*/
 			int nbLang = pNppParam->getNbLang();
-            //::SendDlgItemMessage(_hSelf, IDC_LIST_TABSETTNG, LB_ADDSTRING, 0, (LPARAM)TEXT("[Default]"));
 	        for (int i = 0 ; i < nbLang ; ++i)
             {
 				::SendDlgItemMessage(_hSelf, IDC_LIST_TABSETTNG, LB_ADDSTRING, 0, (LPARAM)pNppParam->getLangFromIndex(i)->_langName.c_str());
             }
-			/*
-            const int index2Begin = 0;
-	        ::SendDlgItemMessage(_hSelf, IDC_LIST_TABSETTNG, LB_SETCURSEL, 0, index2Begin);
-	        ::ShowWindow(::GetDlgItem(_hSelf, IDC_GR_TABVALUE_STATIC), SW_HIDE);
-            ::ShowWindow(::GetDlgItem(_hSelf, IDC_CHECK_DEFAULTTABVALUE), SW_HIDE);
-            ::EnableWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_DISABLE_STATIC), FALSE);            
-            ::ShowWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_DISABLE_STATIC), SW_HIDE);
-			*/
+
 			for (int i = L_TEXT ; i < pNppParam->L_END ; ++i)
 			{
 				generic_string str;
@@ -1521,54 +1515,6 @@ BOOL CALLBACK LangMenuDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM lPara
 		{
 			if (HIWORD(wParam) == LBN_SELCHANGE)
             {
-				/*
-				if (LOWORD(wParam) == IDC_LIST_TABSETTNG)
-				{
-					int index = ::SendDlgItemMessage(_hSelf, IDC_LIST_TABSETTNG, LB_GETCURSEL, 0, 0);
-					if (index == LB_ERR)
-						return FALSE;
-					::ShowWindow(::GetDlgItem(_hSelf, IDC_GR_TABVALUE_STATIC), index?SW_SHOW:SW_HIDE);
-					::ShowWindow(::GetDlgItem(_hSelf, IDC_CHECK_DEFAULTTABVALUE), index?SW_SHOW:SW_HIDE);
-
-					if (index)
-					{
-						Lang *lang = pNppParam->getLangFromIndex(index - 1);
-						if (!lang) return FALSE;
-							bool useDefaultTab = (lang->_tabSize == -1 || lang->_tabSize == 0);
-
-						::SendMessage(::GetDlgItem(_hSelf, IDC_CHECK_DEFAULTTABVALUE), BM_SETCHECK, useDefaultTab, 0);
-						::EnableWindow(::GetDlgItem(_hSelf, IDC_TABSIZE_STATIC), !useDefaultTab);
-
-						int size = useDefaultTab?nppGUI._tabSize:lang->_tabSize;
-						::SetDlgItemInt(_hSelf, IDC_TABSIZEVAL_STATIC, size, FALSE);
-						::SetDlgItemInt(_hSelf, IDC_TABSIZEVAL_DISABLE_STATIC, size, FALSE);
-
-						::EnableWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_STATIC), !useDefaultTab);
-						::ShowWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_DISABLE_STATIC), useDefaultTab);
-						::ShowWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_STATIC), !useDefaultTab);
-						::SendMessage(::GetDlgItem(_hSelf, IDC_CHECK_REPLACEBYSPACE), BM_SETCHECK, useDefaultTab?nppGUI._tabReplacedBySpace:lang->_isTabReplacedBySpace, 0);
-						::EnableWindow(::GetDlgItem(_hSelf, IDC_CHECK_REPLACEBYSPACE), !useDefaultTab);
-
-						if (!useDefaultTab)
-						{
-							::SetDlgItemInt(_hSelf, IDC_TABSIZEVAL_STATIC, lang->_tabSize, FALSE);
-							::SendMessage(::GetDlgItem(_hSelf, IDC_CHECK_REPLACEBYSPACE), BM_SETCHECK, lang->_isTabReplacedBySpace, 0);
-						}
-					}
-					else
-					{
-						::EnableWindow(::GetDlgItem(_hSelf, IDC_TABSIZE_STATIC), TRUE);
-						::EnableWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_STATIC), TRUE);
-						::ShowWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_STATIC), SW_SHOW);
-						::SetDlgItemInt(_hSelf, IDC_TABSIZEVAL_STATIC, nppGUI._tabSize, FALSE);
-						::ShowWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_DISABLE_STATIC), SW_HIDE);
-						::EnableWindow(::GetDlgItem(_hSelf, IDC_CHECK_REPLACEBYSPACE), TRUE);
-						::SendMessage(::GetDlgItem(_hSelf, IDC_CHECK_REPLACEBYSPACE), BM_SETCHECK, nppGUI._tabReplacedBySpace, 0);
-					}
-
-					return TRUE;
-				}
-				*/
 				if (LOWORD(wParam) == IDC_LIST_DISABLEDLANG || LOWORD(wParam) == IDC_LIST_ENABLEDLANG)
 				{
 					HWND hEnableList = ::GetDlgItem(_hSelf, IDC_LIST_ENABLEDLANG);
@@ -1610,95 +1556,6 @@ BOOL CALLBACK LangMenuDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM lPara
 
 			switch (wParam)
             {
-				/*
-                case IDC_TABSIZEVAL_STATIC:
-				{
-            		ValueDlg tabSizeDlg;
-			        tabSizeDlg.init(_hInst, _hParent, nppGUI._tabSize, TEXT("Tab Size : "));
-			        POINT p;
-			        ::GetCursorPos(&p);
-			        int size = tabSizeDlg.doDialog(p);
-			        if (size == -1) return FALSE;
-
-					::SetDlgItemInt(_hSelf, IDC_TABSIZEVAL_STATIC, size, FALSE);
-					::SetDlgItemInt(_hSelf, IDC_TABSIZEVAL_DISABLE_STATIC, size, FALSE);
-
-                    int index = ::SendDlgItemMessage(_hSelf, IDC_LIST_TABSETTNG, LB_GETCURSEL, 0, 0);
-                    if (index == LB_ERR) return FALSE;
-
-                    if (index != 0)
-                    {
-                        Lang *lang = pNppParam->getLangFromIndex(index - 1);
-                        if (!lang) return FALSE;
-                        lang->_tabSize = size;
-
-                        // write in langs.xml
-                        pNppParam->insertTabInfo(lang->getLangName(), lang->getTabInfo());
-                    }
-                    else
-                    {
-                        nppGUI._tabSize = size;
-                    }
-                    
-                    ::SendMessage(::GetParent(_hParent), NPPM_INTERNAL_SETTING_TAB_SIZE, 0, 0);
-					return TRUE;
-				}
-
-				case IDC_CHECK_REPLACEBYSPACE:
-                {
-                    bool isTabReplacedBySpace = BST_CHECKED == ::SendMessage(::GetDlgItem(_hSelf, IDC_CHECK_REPLACEBYSPACE), BM_GETCHECK, 0, 0);
-                    int index = ::SendDlgItemMessage(_hSelf, IDC_LIST_TABSETTNG, LB_GETCURSEL, 0, 0);
-                    if (index == LB_ERR) return FALSE;
-                    if (index != 0)
-                    {
-                        Lang *lang = pNppParam->getLangFromIndex(index - 1);
-                        if (!lang) return FALSE;
-                        if (!lang->_tabSize || lang->_tabSize == -1)
-                            lang->_tabSize = nppGUI._tabSize;
-                        lang->_isTabReplacedBySpace = isTabReplacedBySpace;
-
-                        // write in langs.xml
-                        pNppParam->insertTabInfo(lang->getLangName(), lang->getTabInfo());
-                    }
-                    else
-                    {
-                        nppGUI._tabReplacedBySpace = isTabReplacedBySpace;
-                    }
-					::SendMessage(::GetParent(_hParent), NPPM_INTERNAL_SETTING_TAB_REPLCESPACE, 0, 0);
-					return TRUE;
-                }
-
-                case IDC_CHECK_DEFAULTTABVALUE:
-                {
-                    bool useDefaultTab = BST_CHECKED == ::SendMessage(::GetDlgItem(_hSelf, IDC_CHECK_DEFAULTTABVALUE), BM_GETCHECK, 0, 0);
-                    int index = ::SendDlgItemMessage(_hSelf, IDC_LIST_TABSETTNG, LB_GETCURSEL, 0, 0);
-	                if (index == LB_ERR || index == 0) // index == 0 shouldn't happen
-		                return FALSE;
-
-                    Lang *lang = pNppParam->getLangFromIndex(index - 1);
-                    if (!lang)
-                        return FALSE;
-
-                    //- Set tab setting in choosed language
-                    lang->_tabSize = useDefaultTab?0:nppGUI._tabSize;
-                    lang->_isTabReplacedBySpace = useDefaultTab?false:nppGUI._tabReplacedBySpace;
-
-                    //- set visual effect
-                    ::EnableWindow(::GetDlgItem(_hSelf, IDC_TABSIZE_STATIC), !useDefaultTab);
-					::SetDlgItemInt(_hSelf, IDC_TABSIZEVAL_STATIC, useDefaultTab?nppGUI._tabSize:lang->_tabSize, FALSE);
-                    ::EnableWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_STATIC), !useDefaultTab);
-                    ::ShowWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_DISABLE_STATIC), useDefaultTab);
-                    ::ShowWindow(::GetDlgItem(_hSelf, IDC_TABSIZEVAL_STATIC), !useDefaultTab);
-                    ::SendMessage(::GetDlgItem(_hSelf, IDC_CHECK_REPLACEBYSPACE), BM_SETCHECK, useDefaultTab?nppGUI._tabReplacedBySpace:lang->_isTabReplacedBySpace, 0);
-                    ::EnableWindow(::GetDlgItem(_hSelf, IDC_CHECK_REPLACEBYSPACE), !useDefaultTab);
-
-                    // write in langs.xml
-                    if (useDefaultTab)
-                        pNppParam->insertTabInfo(lang->getLangName(), -1);
-
-                    return TRUE;
-                }
-				*/
 				case IDC_CHECK_LANGMENUCOMPACT : 
 				{
 					nppGUI._isLangMenuCompact = (BST_CHECKED == ::SendMessage(::GetDlgItem(_hSelf, IDC_CHECK_LANGMENUCOMPACT), BM_GETCHECK, 0, 0));
@@ -2300,11 +2157,6 @@ BOOL CALLBACK BackupDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM)
 	{
 		case WM_INITDIALOG :
 		{
-			/*
-			::SetDlgItemInt(_hSelf, IDD_AUTOC_STATIC_N,  nppGUI._autocFromLen, FALSE);
-			_nbCharVal.init(_hInst, _hSelf);
-			_nbCharVal.create(::GetDlgItem(_hSelf, IDD_AUTOC_STATIC_N), IDD_AUTOC_STATIC_N);
-			*/
 			int ID2Check = 0;
 
 			switch (nppGUI._backup)
@@ -2325,23 +2177,7 @@ BOOL CALLBACK BackupDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM)
 				::SendDlgItemMessage(_hSelf, IDC_BACKUPDIR_CHECK, BM_SETCHECK, BST_CHECKED, 0);
 
 			::SendDlgItemMessage(_hSelf, IDC_BACKUPDIR_EDIT, WM_SETTEXT, 0, (LPARAM)nppGUI._backupDir.c_str());
-			/*
-			bool isEnableAutoC = nppGUI._autocStatus != nppGUI.autoc_none;
 
-			::SendDlgItemMessage(_hSelf, IDD_AUTOC_ENABLECHECK, BM_SETCHECK, isEnableAutoC?BST_CHECKED:BST_UNCHECKED, 0);
-			::SendDlgItemMessage(_hSelf, IDD_AUTOC_FUNCRADIO, BM_SETCHECK, nppGUI._autocStatus == nppGUI.autoc_func?BST_CHECKED:BST_UNCHECKED, 0);
-			::SendDlgItemMessage(_hSelf, IDD_AUTOC_WORDRADIO, BM_SETCHECK, nppGUI._autocStatus == nppGUI.autoc_word?BST_CHECKED:BST_UNCHECKED, 0);
-			::SendDlgItemMessage(_hSelf, IDD_FUNC_CHECK, BM_SETCHECK, nppGUI._funcParams?BST_CHECKED:BST_UNCHECKED, 0);
-			if (!isEnableAutoC)
-			{
-				::EnableWindow(::GetDlgItem(_hSelf, IDD_AUTOC_FUNCRADIO), FALSE);
-				::EnableWindow(::GetDlgItem(_hSelf, IDD_AUTOC_WORDRADIO), FALSE);
-				::EnableWindow(::GetDlgItem(_hSelf, IDD_AUTOC_STATIC_FROM), FALSE);
-				::EnableWindow(::GetDlgItem(_hSelf, IDD_AUTOC_STATIC_N), FALSE);
-				::EnableWindow(::GetDlgItem(_hSelf, IDD_AUTOC_STATIC_CHAR), FALSE);
-				::EnableWindow(::GetDlgItem(_hSelf, IDD_AUTOC_STATIC_NOTE), FALSE);
-			}
-			*/
 			updateBackupGUI();
 			return TRUE;
 		}
@@ -2549,4 +2385,50 @@ BOOL CALLBACK AutoCompletionDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM
 		}
 	}
 	return FALSE;
-}
\ No newline at end of file
+}
+
+
+BOOL CALLBACK MultiInstDlg::run_dlgProc(UINT Message, WPARAM wParam, LPARAM)
+{
+	NppGUI & nppGUI = (NppGUI &)((NppParameters::getInstance())->getNppGUI());
+	switch (Message) 
+	{
+		case WM_INITDIALOG :
+		{
+			MultiInstSetting multiInstSetting = nppGUI._multiInstSetting;
+
+			::SendDlgItemMessage(_hSelf, IDC_SESSIONININST_RADIO, BM_SETCHECK, multiInstSetting == multiInstOnSession?BST_CHECKED:BST_UNCHECKED, 0);
+			::SendDlgItemMessage(_hSelf, IDC_MULTIINST_RADIO, BM_SETCHECK, multiInstSetting == multiInst?BST_CHECKED:BST_UNCHECKED, 0);
+			::SendDlgItemMessage(_hSelf, IDC_MONOINST_RADIO, BM_SETCHECK, multiInstSetting == monoInst?BST_CHECKED:BST_UNCHECKED, 0);
+		}
+		break;
+		case WM_COMMAND : 
+		{
+			switch (wParam)
+			{
+				case IDC_SESSIONININST_RADIO :
+				{
+					nppGUI._multiInstSetting = multiInstOnSession;
+				}
+				break;
+
+				case IDC_MULTIINST_RADIO :
+				{
+					nppGUI._multiInstSetting = multiInst;
+				}
+				break;
+
+				case IDC_MONOINST_RADIO :
+				{
+					nppGUI._multiInstSetting = monoInst;
+				}
+				break;
+				default :
+					return FALSE;
+			}
+		}
+		break;
+	}
+
+	return FALSE;
+}
diff --git a/PowerEditor/src/WinControls/Preference/preferenceDlg.h b/PowerEditor/src/WinControls/Preference/preferenceDlg.h
index 92ea33ed..417fb98a 100644
--- a/PowerEditor/src/WinControls/Preference/preferenceDlg.h
+++ b/PowerEditor/src/WinControls/Preference/preferenceDlg.h
@@ -95,22 +95,14 @@ class DefaultNewDocDlg : public StaticDialog
 {
 public :
 	DefaultNewDocDlg() {};
-	/*
-	virtual void destroy() {
-		_nbHistoryVal.destroy();
-		_customLenVal.destroy();
-	};
-	*/
+
 private :
-	//URLCtrl _nbHistoryVal;
-	//URLCtrl _customLenVal;
 	std::vector<LangID_Name> _langList;
 	void makeOpenAnsiAsUtf8(bool doIt){
 		if (!doIt)
 			::SendDlgItemMessage(_hSelf, IDC_CHECK_OPENANSIASUTF8, BM_SETCHECK, BST_UNCHECKED, 0);
 		::EnableWindow(::GetDlgItem(_hSelf, IDC_CHECK_OPENANSIASUTF8), doIt);
 	};
-	//void setCustomLen(int val);
 	BOOL CALLBACK run_dlgProc(UINT Message, WPARAM wParam, LPARAM lParam);
 };
 
@@ -118,24 +110,8 @@ class DefaultDirectoryDlg : public StaticDialog
 {
 public :
 	DefaultDirectoryDlg() {};
-	/*
-	virtual void destroy() {
-		_nbHistoryVal.destroy();
-		_customLenVal.destroy();
-	};
-	*/
+
 private :
-	//URLCtrl _nbHistoryVal;
-	//URLCtrl _customLenVal;
-	//std::vector<LangID_Name> _langList;
-	/*
-	void makeOpenAnsiAsUtf8(bool doIt){
-		if (!doIt)
-			::SendDlgItemMessage(_hSelf, IDC_CHECK_OPENANSIASUTF8, BM_SETCHECK, BST_UNCHECKED, 0);
-		::EnableWindow(::GetDlgItem(_hSelf, IDC_CHECK_OPENANSIASUTF8), doIt);
-	};
-	*/
-	//void setCustomLen(int val);
 	BOOL CALLBACK run_dlgProc(UINT Message, WPARAM wParam, LPARAM lParam);
 };
 
@@ -159,14 +135,8 @@ class LangMenuDlg : public StaticDialog
 {
 public :
 	LangMenuDlg() {};
-	/*
-    virtual void destroy() {
-		_tabSizeVal.destroy();
-	};
-	*/
 
 private :
-    //URLCtrl _tabSizeVal;
     LexerStylerArray _lsArray;
 	BOOL CALLBACK run_dlgProc(UINT Message, WPARAM wParam, LPARAM lParam);
 	vector<LangMenuItem> _langList;
@@ -209,7 +179,6 @@ class BackupDlg : public StaticDialog
 public :
 	BackupDlg() {};
 private :
-	//URLCtrl _nbCharVal;
 	void updateBackupGUI();
 	BOOL CALLBACK run_dlgProc(UINT Message, WPARAM wParam, LPARAM lParam);
 };
@@ -221,10 +190,17 @@ public :
 	AutoCompletionDlg() {};
 private :
 	URLCtrl _nbCharVal;
-	//void updateAutoCompletionGUI();
 	BOOL CALLBACK run_dlgProc(UINT Message, WPARAM wParam, LPARAM lParam);
 };
 
+class MultiInstDlg : public StaticDialog
+{
+public :
+	MultiInstDlg() {};
+
+private :
+	BOOL CALLBACK run_dlgProc(UINT Message, WPARAM wParam, LPARAM lParam);
+};
 
 class PreferenceDlg : public StaticDialog
 {
@@ -246,17 +222,14 @@ public :
 	    display();
     };
 	bool renameDialogTitle(const TCHAR *internalName, const TCHAR *newName);
-
-	virtual void destroy() {
-		//_ctrlTab.destroy();
-		_barsDlg.destroy();
-		_marginsDlg.destroy();
-		_settingsDlg.destroy();
-		_fileAssocDlg.destroy();
-		_langMenuDlg.destroy();
-		_printSettingsDlg.destroy();
-		_defaultNewDocDlg.destroy();
+	
+	int getListSelectedIndex() const {
+		return ::SendDlgItemMessage(_hSelf, IDC_LIST_DLGTITLE, LB_GETCURSEL, 0, 0);
 	};
+	void setListSelection(size_t currentSel) const;
+
+	virtual void destroy();
+
 private :
 	BOOL CALLBACK run_dlgProc(UINT Message, WPARAM wParam, LPARAM lParam);
 	void makeCategoryList();
@@ -275,6 +248,7 @@ private :
 	RecentFilesHistoryDlg _recentFilesHistoryDlg;
 	BackupDlg _backupDlg;
 	AutoCompletionDlg _autoCompletionDlg;
+	MultiInstDlg _multiInstDlg;
 };
 
 
diff --git a/PowerEditor/src/WinControls/Preference/preference_rc.h b/PowerEditor/src/WinControls/Preference/preference_rc.h
index 252f8187..1196db44 100644
--- a/PowerEditor/src/WinControls/Preference/preference_rc.h
+++ b/PowerEditor/src/WinControls/Preference/preference_rc.h
@@ -62,6 +62,12 @@
 	#define	IDC_DOCSWITCH_GB_STATIC (IDD_PREFERENCE_BAR_BOX + 25)
 	#define	IDC_CHECK_DOCSWITCH (IDD_PREFERENCE_BAR_BOX + 26)
 
+#define	IDD_PREFERENCE_MULTIINSTANCE_BOX 6150 //(IDD_PREFERENCE_BOX + 150)
+	#define	IDC_MULTIINST_GB_STATIC (IDD_PREFERENCE_MULTIINSTANCE_BOX + 1)
+	#define	IDC_SESSIONININST_RADIO (IDD_PREFERENCE_MULTIINSTANCE_BOX + 2)
+	#define	IDC_MULTIINST_RADIO (IDD_PREFERENCE_MULTIINSTANCE_BOX + 3)
+	#define	IDC_MONOINST_RADIO (IDD_PREFERENCE_MULTIINSTANCE_BOX + 4)
+
 #define	IDD_PREFERENCE_MARGEIN_BOX 6200 //(IDD_PREFERENCE_BOX + 200)
 	#define	IDC_FMS_GB_STATIC (IDD_PREFERENCE_MARGEIN_BOX + 1)
 	#define	IDC_RADIO_SIMPLE (IDD_PREFERENCE_MARGEIN_BOX + 2)
diff --git a/PowerEditor/src/config.model.xml b/PowerEditor/src/config.model.xml
index e2ef2854..b92c8e2e 100644
--- a/PowerEditor/src/config.model.xml
+++ b/PowerEditor/src/config.model.xml
@@ -74,6 +74,7 @@
         <GUIConfig name="URL">2</GUIConfig>
         <GUIConfig name="globalOverride" fg="no" bg="no" font="no" fontSize="no" bold="no" italic="no" underline="no" />
         <GUIConfig name="auto-completion" autoCAction="0" triggerFromNbChar="1" />
+        <GUIConfig name="multiInst" setting="0" />
         <GUIConfig name="sessionExt"></GUIConfig>
     </GUIConfigs>
     <!-- The History of opened files list -->
diff --git a/PowerEditor/src/langs.model.xml b/PowerEditor/src/langs.model.xml
index 95accc31..3e9eb967 100644
--- a/PowerEditor/src/langs.model.xml
+++ b/PowerEditor/src/langs.model.xml
@@ -214,7 +214,7 @@
             <Keywords name="type3">std ieee work standard textio std_logic_1164 std_logic_arith std_logic_misc std_logic_signed std_logic_textio std_logic_unsigned numeric_bit numeric_std math_complex math_real vital_primitives vital_timing</Keywords>
             <Keywords name="type4">boolean bit character severity_level integer real time delay_length natural positive string bit_vector file_open_kind file_open_status line text side width std_ulogic std_ulogic_vector std_logic std_logic_vector X01 X01Z UX01 UX01Z unsigned signed</Keywords>
         </Language>
-        <Language name="xml" ext="xml xsml xsl xsd kml wsdl" commentLine="" commentStart="&lt;!--" commentEnd="--&gt;">
+        <Language name="xml" ext="xml xsml xsl xsd kml wsdl xlf xliff" commentLine="" commentStart="&lt;!--" commentEnd="--&gt;">
         </Language>
         <Language name="yaml" ext="yml" commentLine="#">
         </Language>
diff --git a/PowerEditor/src/localization.cpp b/PowerEditor/src/localization.cpp
index 8848c8e5..bcd60075 100644
--- a/PowerEditor/src/localization.cpp
+++ b/PowerEditor/src/localization.cpp
@@ -860,12 +860,11 @@ void NativeLangSpeaker::changeFindReplaceDlgLang(FindReplaceDlg & findReplaceDlg
 
 void NativeLangSpeaker::changePrefereceDlgLang(PreferenceDlg & preference) 
 {
+	int currentSel = preference.getListSelectedIndex();
 	changeDlgLang(preference.getHSelf(), "Preference");
 
-	char titre[128];
-
 	WcharMbcsConvertor *wmc = WcharMbcsConvertor::getInstance();
-
+	char titre[128];
 	changeDlgLang(preference._barsDlg.getHSelf(), "Global", titre);
 	if (titre[0] != '\0')
 	{
@@ -946,6 +945,8 @@ void NativeLangSpeaker::changePrefereceDlgLang(PreferenceDlg & preference)
 		const wchar_t *nameW = wmc->char2wchar(titre, _nativeLangEncoding);
 		preference.renameDialogTitle(TEXT("AutoCompletion"), nameW);
 	}
+
+	preference.setListSelection(currentSel);
 }
 
 void NativeLangSpeaker::changeShortcutLang()
diff --git a/PowerEditor/src/winmain.cpp b/PowerEditor/src/winmain.cpp
index fe112629..969ff714 100644
--- a/PowerEditor/src/winmain.cpp
+++ b/PowerEditor/src/winmain.cpp
@@ -178,6 +178,7 @@ const TCHAR FLAG_SYSTRAY[] = TEXT("-systemtray");
 const TCHAR FLAG_LOADINGTIME[] = TEXT("-loadingTime");
 const TCHAR FLAG_HELP[] = TEXT("--help");
 const TCHAR FLAG_ALWAYS_ON_TOP[] = TEXT("-alwaysOnTop");
+const TCHAR FLAG_OPENSESSIONFILE[] = TEXT("-openSession");
 
 const TCHAR COMMAND_ARG_HELP[] = TEXT("Usage :\r\
 \r\
@@ -197,6 +198,7 @@ notepad++ [--help] [-multiInst] [-noPlugin] [-lLanguage] [-nLineNumber] [-cColum
     -systemtray : Launch Notepad++ directly in system tray\r\
     -loadingTime : Display Notepad++ loading time\r\
     -alwaysOnTop : Make Notepad++ always on top\r\
+	-openSession : Open a specific session. fullFilePathName must be a session file\r\
     fullFilePathName : file name to open (absolute or relative path name)\r\
 ");
 
@@ -228,18 +230,21 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR, int)
 	cmdLineParams._isPreLaunch = isInList(FLAG_SYSTRAY, params);
 	cmdLineParams._alwaysOnTop = isInList(FLAG_ALWAYS_ON_TOP, params);
 	cmdLineParams._showLoadingTime = isInList(FLAG_LOADINGTIME, params);
+	cmdLineParams._isSessionFile = isInList(FLAG_OPENSESSIONFILE, params);
 	cmdLineParams._langType = getLangTypeFromParam(params);
 	cmdLineParams._line2go = getNumberFromParam('n', params, isParamePresent);
     cmdLineParams._column2go = getNumberFromParam('c', params, isParamePresent);
 	cmdLineParams._point.x = getNumberFromParam('x', params, cmdLineParams._isPointXValid);
 	cmdLineParams._point.y = getNumberFromParam('y', params, cmdLineParams._isPointYValid);
-
+	
 	if (showHelp)
 	{
 		::MessageBox(NULL, COMMAND_ARG_HELP, TEXT("Notepad++ Command Argument Help"), MB_OK);
 	}
 
 	NppParameters *pNppParameters = NppParameters::getInstance();
+	pNppParameters->load();
+
 	// override the settings if notepad style is present
 	if (pNppParameters->asNotepadStyle())
 	{
@@ -248,6 +253,16 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR, int)
 		cmdLineParams._isNoSession = true;
 	}
 
+	// override the settings if multiInst is choosen by user in the preference dialog
+	const NppGUI & nppGUI = pNppParameters->getNppGUI();
+	if (nppGUI._multiInstSetting == multiInst)
+	{
+		isMultiInst = true;
+		// Only the first launch remembers the session
+		if (!TheFirstOne)
+			cmdLineParams._isNoSession = true;
+	}
+
 	generic_string quotFileName = TEXT("");
     // tell the running instance the FULL path to the new files to load
 	size_t nrFilesToOpen = params.size();
@@ -331,7 +346,6 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR, int)
         }
 	}
 
-	pNppParameters->load();
 	Notepad_plus_Window notepad_plus_plus;
 	
 	NppGUI & nppGui = (NppGUI &)pNppParameters->getNppGUI();