[Installer] Installing an update in silent mode fails *and* removes the existing version

[argonym]

To Reproduce

1. Have Greenshot installed (for ALLUSERS)
2. Make sure it's running for at least one user
3. Install a newer version in silent mode (/VERYSILENT /SUPPRESSMSGBOXES /NORESTART ) and as SYSTEM
4. Notice that it has been uninstalled (at least partially).

Expected behavior If Greenshot is running, the upgrade may fail. But the current installation must not be removed. Additionally, it would be nice if #524 or even #516 were implemented/fixed.

Versions

• Greenshot version 1.3.304
• Inno Setup version 6.2.1

Setup log

2025-11-25 15:37:49.815   Log opened. (Time zone: UTC+01:00)
2025-11-25 15:37:49.815   Setup version: Inno Setup version 6.2.1
2025-11-25 15:37:49.816   Original Setup EXE: C:\Users\WINDEP~1\AppData\Local\Temp\WinGet\Greenshot.Greenshot.1.3.304\Greenshot-INSTALLER-1.3.304-RELEASE.exe
2025-11-25 15:37:49.816   Setup command line: /SL5="$9D0062,3032205,791552,C:\Users\WINDEP~1\AppData\Local\Temp\WinGet\Greenshot.Greenshot.1.3.304\Greenshot-INSTALLER-1.3.304-RELEASE.exe" /SP- /VERYSILENT /SUPPRESSMSGBOXES /NORESTART /LOG="C:\Users\WinDeploy\AppData\Local\Packages\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe\LocalState\DiagOutputDir\Greenshot.Greenshot.1.3.304-25-11-25-15-37-47.log" /ALLUSERS
2025-11-25 15:37:49.816   Windows version: 10.0.26100  (NT platform: Yes)
2025-11-25 15:37:49.816   64-bit Windows: Yes
2025-11-25 15:37:49.816   Processor architecture: x64
2025-11-25 15:37:49.816   User privileges: Administrative
2025-11-25 15:37:49.822   Administrative install mode: Yes
2025-11-25 15:37:49.822   Install mode root key: HKEY_LOCAL_MACHINE
2025-11-25 15:37:49.822   64-bit install mode: Yes
2025-11-25 15:37:49.839   Created temporary directory: C:\Users\WINDEP~1\AppData\Local\Temp\is-K5OCB.tmp
2025-11-25 15:37:49.876   -- DLL function import --
2025-11-25 15:37:49.876   Function name: isxdl_AddFile
2025-11-25 15:37:49.876   DLL name: files:isxdl.dll
2025-11-25 15:37:49.877   Extracting temporary file: C:\Users\WINDEP~1\AppData\Local\Temp\is-K5OCB.tmp\isxdl.dll
2025-11-25 15:37:49.912   Dest DLL name: C:\Users\WINDEP~1\AppData\Local\Temp\is-K5OCB.tmp\isxdl.dll
2025-11-25 15:37:49.912   Importing the DLL function.
2025-11-25 15:37:49.949   Successfully imported the DLL function. Delay loaded? No
2025-11-25 15:37:49.949   -- DLL function import --
2025-11-25 15:37:49.950   Function name: isxdl_DownloadFiles
2025-11-25 15:37:49.950   DLL name: files:isxdl.dll
2025-11-25 15:37:49.950   Dest DLL name: C:\Users\WINDEP~1\AppData\Local\Temp\is-K5OCB.tmp\isxdl.dll
2025-11-25 15:37:49.950   Importing the DLL function.
2025-11-25 15:37:49.950   Successfully imported the DLL function. Delay loaded? No
2025-11-25 15:37:49.950   -- DLL function import --
2025-11-25 15:37:49.950   Function name: isxdl_SetOption
2025-11-25 15:37:49.950   DLL name: files:isxdl.dll
2025-11-25 15:37:49.950   Dest DLL name: C:\Users\WINDEP~1\AppData\Local\Temp\is-K5OCB.tmp\isxdl.dll
2025-11-25 15:37:49.950   Importing the DLL function.
2025-11-25 15:37:49.950   Successfully imported the DLL function. Delay loaded? No
2025-11-25 15:37:50.284   Found 41 files to register with RestartManager.
2025-11-25 15:37:50.284   Calling RestartManager's RmGetList.
2025-11-25 15:37:50.650   RmGetList finished successfully.
2025-11-25 15:37:50.650   RestartManager found an application using one of our files: Greenshot
2025-11-25 15:37:50.650   Can use RestartManager to avoid reboot? No (2: Session Mismatch)
2025-11-25 15:37:55.621   Starting the installation process.
2025-11-25 15:37:55.627   Directory for uninstall files: C:\Program Files\Greenshot
2025-11-25 15:37:55.628   Creating new uninstall log: C:\Program Files\Greenshot\unins000.dat
2025-11-25 15:37:55.639   -- File entry --
2025-11-25 15:37:55.639   Dest filename: C:\Program Files\Greenshot\unins000.exe
2025-11-25 15:37:55.639   Non-default bitness: 32-bit
2025-11-25 15:37:55.657   Time stamp of our file: 2025-11-25 15:37:48.577
2025-11-25 15:37:55.657   Installing the file.
2025-11-25 15:37:55.731   Successfully installed the file.
2025-11-25 15:37:55.731   -- File entry --
2025-11-25 15:37:55.731   Dest filename: C:\Program Files\Greenshot\Greenshot.exe
2025-11-25 15:37:55.732   Time stamp of our file: 2025-10-30 18:05:08.000
2025-11-25 15:37:55.732   Dest file exists.
2025-11-25 15:37:55.732   Time stamp of existing file: 2017-01-28 15:58:38.000
2025-11-25 15:37:55.732   Installing the file.
2025-11-25 15:37:55.791   DeleteFile: The existing file appears to be in use (5). Retrying.
2025-11-25 15:37:56.796   DeleteFile: The existing file appears to be in use (5). Retrying.
2025-11-25 15:37:57.814   DeleteFile: The existing file appears to be in use (5). Retrying.
2025-11-25 15:37:58.830   DeleteFile: The existing file appears to be in use (5). Retrying.
2025-11-25 15:37:59.851   Defaulting to Abort for suppressed message box (Abort/Retry/Ignore):
                          C:\Program Files\Greenshot\Greenshot.exe
                          
                          Error when attempting to replace an existing file:
                          DeleteFile failed; Code 5.
                          Access denied.
2025-11-25 15:37:59.851   User canceled the installation process.
2025-11-25 15:37:59.851   Rolling back changes.
2025-11-25 15:37:59.864   Starting the uninstallation process.
2025-11-25 15:37:59.864   Uninstallation process succeeded.
2025-11-25 15:37:59.865   Deinitializing Setup.
2025-11-25 15:37:59.934   Log closed.