diff --git a/InnoSetupScript/Custom_Messages.iss b/InnoSetupScript/Custom_Messages.iss
index 305332e78..44bc39497 100644
--- a/InnoSetupScript/Custom_Messages.iss
+++ b/InnoSetupScript/Custom_Messages.iss
@@ -24,6 +24,7 @@
 
 ;English
 en.msg_SetupIsRunningWarning=Subtitle Edit Setup is already running!
+en.msg_AppIsRunning=Subtitle Edit is running! Please close it before proceeding.
 en.msg_AskToDownNET=Subtitle Edit requires the .NET Framework 2.0. Please download and install the .NET Framework and run setup again. %n%nDo you want to download the .NET Framework 2.0 now?
 en.msg_DeleteSettings=Do you also want to delete Subtitle Edit's settings and any custom changes you made in the dictionaries? %n%nIf you plan on reinstalling Subtitle Edit you do not have to delete them.
 en.run_VisitWebsite=Visit Subtitle Edit's Website
@@ -36,6 +37,7 @@ en.tsk_ResetSettings=Reset Subtitle Edit's settings
 
 
 dk.msg_SetupIsRunningWarning=Subtitle Edit Setup kører allerede!
+dk.msg_AppIsRunning=Subtitle Edit is running! Please close it before proceeding.
 dk.msg_AskToDownNET=Subtitle Edit kræver .NET Framework 2.0. Download and installer .NET Framework og kør setup igen. %n%nVil du downloade .NET Framework 2.0 nu?
 dk.msg_DeleteSettings=Vil du også slette Subtitle Edit's indstillinger og evt. ændringer i ordlister? %n%nHvis du vil geninstallere Subtitle Edit senere kan du beholde disse indstillinger.
 dk.run_VisitWebsite=Besøg Subtitle Edits Website
@@ -48,6 +50,7 @@ dk.tsk_ResetSettings=Nulstil Subtitle Edit indstillinger
 
 
 es.msg_SetupIsRunningWarning=Subtitle Edit Setup is already running!
+es.msg_AppIsRunning=Subtitle Edit is running! Please close it before proceeding.
 es.msg_AskToDownNET=Subtitle Edit requires the .NET Framework 2.0. Please download and install the .NET Framework and run setup again. %n%nDo you want to download the .NET Framework 2.0 now?
 es.msg_DeleteSettings=Do you also want to delete Subtitle Edit's settings and any custom changes you made in the dictionaries? %n%nIf you plan on reinstalling Subtitle Edit you do not have to delete them.
 es.run_VisitWebsite=Visit Subtitle Edit's Website
@@ -60,6 +63,7 @@ es.tsk_ResetSettings=Reset Subtitle Edit's settings
 
 
 fr.msg_SetupIsRunningWarning=Subtitle Edit Setup is already running!
+fr.msg_AppIsRunning=Subtitle Edit is running! Please close it before proceeding.
 fr.msg_AskToDownNET=Subtitle Edit requires the .NET Framework 2.0. Please download and install the .NET Framework and run setup again. %n%nDo you want to download the .NET Framework 2.0 now?
 fr.msg_DeleteSettings=Do you also want to delete Subtitle Edit's settings and any custom changes you made in the dictionaries? %n%nIf you plan on reinstalling Subtitle Edit you do not have to delete them.
 fr.run_VisitWebsite=Visit Subtitle Edit's Website
@@ -72,6 +76,7 @@ fr.tsk_ResetSettings=Reset Subtitle Edit's settings
 
 
 it.msg_SetupIsRunningWarning=Subtitle Edit Setup is already running!
+it.msg_AppIsRunning=Subtitle Edit is running! Please close it before proceeding.
 it.msg_AskToDownNET=Subtitle Edit requires the .NET Framework 2.0. Please download and install the .NET Framework and run setup again. %n%nDo you want to download the .NET Framework 2.0 now?
 it.msg_DeleteSettings=Do you also want to delete Subtitle Edit's settings and any custom changes you made in the dictionaries? %n%nIf you plan on reinstalling Subtitle Edit you do not have to delete them.
 it.run_VisitWebsite=Visit Subtitle Edit's Website
@@ -84,6 +89,7 @@ it.tsk_ResetSettings=Reset Subtitle Edit's settings
 
 
 nl.msg_SetupIsRunningWarning=Subtitle Edit Setup is already running!
+nl.msg_AppIsRunning=Subtitle Edit is running! Please close it before proceeding.
 nl.msg_AskToDownNET=Subtitle Edit requires the .NET Framework 2.0. Please download and install the .NET Framework and run setup again. %n%nDo you want to download the .NET Framework 2.0 now?
 nl.msg_DeleteSettings=Do you also want to delete Subtitle Edit's settings and any custom changes you made in the dictionaries? %n%nIf you plan on reinstalling Subtitle Edit you do not have to delete them.
 nl.run_VisitWebsite=Visit Subtitle Edit's Website
@@ -96,6 +102,7 @@ nl.tsk_ResetSettings=Reset Subtitle Edit's settings
 
 
 pl.msg_SetupIsRunningWarning=Subtitle Edit Setup is already running!
+pl.msg_AppIsRunning=Subtitle Edit is running! Please close it before proceeding.
 pl.msg_AskToDownNET=Subtitle Edit requires the .NET Framework 2.0. Please download and install the .NET Framework and run setup again. %n%nDo you want to download the .NET Framework 2.0 now?
 pl.msg_DeleteSettings=Do you also want to delete Subtitle Edit's settings and any custom changes you made in the dictionaries? %n%nIf you plan on reinstalling Subtitle Edit you do not have to delete them.
 pl.run_VisitWebsite=Visit Subtitle Edit's Website
@@ -107,6 +114,7 @@ pl.tsk_Other=Other:
 pl.tsk_ResetSettings=Reset Subtitle Edit's settings
 
 ro.msg_SetupIsRunningWarning=Instalarea programului Subtitle Edit se efectuează deja!
+ro.msg_AppIsRunning=Subtitle Edit is running! Please close it before proceeding.
 ro.msg_AskToDownNET=Subtitle Edit necesită .NET Framework 2.0. Vă rog să descărcaţi şi să instalaţi .NET Framework şi apoi reinstalaţi. %n%nVreţi să descărcaţi acum .NET Framework 2.0?
 ro.msg_DeleteSettings=Vreţi de asemenea să ştergeţi setările şi personalizările făcute în dicţionare? %n%nDacă aveţi de gând să reinstalaţi Subtitle Edit, nu este nevoie să le ştergeţi.
 ro.run_VisitWebsite=Vizitaţi pagina Web a programului Subtitle Edit
diff --git a/InnoSetupScript/Subtitle_Edit_installer.iss b/InnoSetupScript/Subtitle_Edit_installer.iss
index ca6e43291..e1621b3b8 100644
--- a/InnoSetupScript/Subtitle_Edit_installer.iss
+++ b/InnoSetupScript/Subtitle_Edit_installer.iss
@@ -21,7 +21,7 @@
 ; Inno Setup QuickStart Pack Unicode v5.3.11(+): http://www.jrsoftware.org/isdl.php#qsp
 
 
-#define installer_build_number "04"
+#define installer_build_number "05"
 
 #define VerMajor
 #define VerMinor
@@ -113,6 +113,7 @@ Name: reset_settings; Description: {cm:tsk_ResetSettings}; GroupDescription: {cm
 
 
 [Files]
+Source: psvince.dll; DestDir: {app}; Flags: ignoreversion
 Source: ..\src\Changelog.txt; DestDir: {app}; Flags: ignoreversion
 Source: ..\src\gpl.txt; DestDir: {app}; Flags: ignoreversion
 Source: ..\src\Bin\Release\Hunspellx86.dll; DestDir: {app}; Flags: ignoreversion
@@ -187,6 +188,15 @@ var
   is_update: Boolean;
 
 
+// General functions
+function IsModuleLoaded(modulename: AnsiString ):  Boolean;
+external 'IsModuleLoaded@files:psvince.dll stdcall setuponly';
+
+
+function IsModuleLoadedU(modulename: AnsiString ):  Boolean;
+external 'IsModuleLoaded@{app}\psvince.dll stdcall uninstallonly';
+
+
 // Check if Subtitle Edit's settings exist
 function SettingsExistCheck(): Boolean;
 begin
@@ -264,11 +274,18 @@ begin
   // Create a mutex for the installer and if it's already running then expose a message and stop installation
   if CheckForMutexes(installer_mutex_name) then begin
     if not WizardSilent() then
-      MsgBox(ExpandConstant('{cm:msg_SetupIsRunningWarning}'), mbCriticalError, MB_OK);
+      MsgBox(ExpandConstant('{cm:msg_SetupIsRunningWarning}'), mbError, MB_OK);
     exit;
   end;
   CreateMutex(installer_mutex_name);
 
+  if IsModuleLoaded( 'SubtitleEdit.exe' ) then begin
+    MsgBox(ExpandConstant('{cm:msg_AppIsRunning}'), mbError, MB_OK );
+    Result := False;
+    Abort;
+  end else
+    Result := True;
+
   // Check if .NET Framework 2.0 is installed and if not offer to download it
   try
     ExpandConstant('{dotnet20}');
@@ -293,11 +310,25 @@ end;
 
 function InitializeUninstall(): Boolean;
 begin
-  Result := True;
-  if CheckForMutexes(installer_mutex_name) then begin
-    if not WizardSilent() then
-      MsgBox(ExpandConstant('{cm:msg_SetupIsRunningWarning}'), mbCriticalError, MB_OK);
-      exit;
-   end;
-   CreateMutex(installer_mutex_name);
+  // Check if app is running during uninstallation
+  if IsModuleLoadedU( 'SubtitleEdit.exe' ) then begin
+      MsgBox(ExpandConstant('{cm:msg_AppIsRunning}'), mbError, MB_OK );
+      Result := False;
+  end
+  else Result := True;
+
+  if NOT IsModuleLoadedU( 'SubtitleEdit.exe' ) then begin
+      Result := True;
+      if CheckForMutexes(installer_mutex_name) then begin
+        if not WizardSilent() then
+        MsgBox(ExpandConstant('{cm:msg_SetupIsRunningWarning}'), mbError, MB_OK);
+        Result := False;
+      end
+      else begin
+        CreateMutex(installer_mutex_name);
+      end;
+  end;
+
+  // Unload the psvince.dll in order to be uninstalled
+  UnloadDLL(ExpandConstant('{app}\psvince.dll'));
 end;
diff --git a/InnoSetupScript/psvince.dll b/InnoSetupScript/psvince.dll
new file mode 100644
index 000000000..e910509d0
Binary files /dev/null and b/InnoSetupScript/psvince.dll differ