PatchMyPC Home Updater won't run

[Marvalsys]

I have a friend I'm trying to help who is elderly and not very good with tech. She has Win11 Home 25H2 and had been using PatchMyPC Home Updater until I recently noticed it wasn't running. I had to do a non-destructive Windows reinstall from the Settings > System > Recovery screen to overcome some corruption that SFC and DISM couldn't handle, made sure to recheck the .NET Framework 3.5 in Windows Features from Control Panel, and have tried several times to uninstall, download, and reinstall PMPC v.5.4.3.1. Each time the install ends with no indication of success or failure and the program doesn't run (it does display the UAC prompt but the UI never appears). How do I proceed?

[Marvalsys]

Forgot to include that the most recent uninstall was done using Revo Uninstaller's Advanced scan to find and delete all traces of PMPC - still didn't help.

[Treefrog125]

I have also had the same issue on my son's pc more recently. Re-installing Patch My PC Home Updater ver: 5450.
The old version was uninstalled using Revo Uninstaller, and removing all left over elements.
Installed the new version 5450 and similar to the last person: Marvalsys. It displays the UAC Prompt to run the program then nothing after that, no error, no running program...
I tried re-uninstalling using Revo, also checked to make sure the registry was clean at "HKLM\Software\PatchMyPC" no longer there...
Also cleared out the %TEMP% folder and C:\WINDOWS\TEMP folders.
Made sure .NET Framework 3.5 in Windows features was disabled and re-enabled after a restart between each selection.
Uninstalled the newer .NET Framework 10 SDK and .NET Framework Runtime 9.0.20, then re-installed .NET Framework 10 SDK.
Also ran following in command prompt:
CHKDSK C: /F /V /R - on SSD for main drive where windows is installed.
Then ran following DSIM Commands to verify system files ok:
Dism /Online /Cleanup-Image /StartComponentCleanup
Dism /Online /Cleanup-Image /RestoreHealth
SFC /scannow
It fixed a System File Corruption so I then re-started the pc and tried to re-install PatchMyPC Home Updater on it, and still nothing after the UAC prompt.

I get the feeling somehow that my son's pc has updated the .NET Framework at some stage and I'm wondering if Patch My PC is still looking for the old runtime, but can't find it...

Any ideas anyone???