Installer - add check for running instance

[user0]

XnViewMP 1.11.7
Windows11 (25H2), display resolution 3840x2160, dpi scale 150%

Installer
when app instance is running:
- installation (update) fails with 'DeleteFile, code 5' (Access denied) on some files (QtConcurrent.dll, mdk.dll, msvcp140_1.dll, etc)
- uninstallation leaves files undeleted

installer_error5.png

Suggestion

• add a running-instance check to Inno Setup
  - (optional) add RestartApplications=yes

  Code: Select all

  [Setup]
  AppMutex=XnViewMP_Running
  CloseApplications=yes
  RestartApplications=yes
  

  same behaviour as running current installer with /CLOSEAPPLICATIONS flag