Thank you for this, I've been reinstalling Windows 11 over the last few hours and it would constantly brick.
In Winapp2, I changed things to the following
[Windows Temporary Files *]
LangSecRef=3025
Detect=HKLM\Software\Microsoft\Windows
FileKey1=%SystemDrive%\Documents and Settings\LocalService*\Local Settings\Temp|*|RECURSE
FileKey2=%SystemDrive%\Documents and Settings\NetworkService*\Local Settings\Temp|*|RECURSE
FileKey3=%WinDir%\ServiceProfiles\*\AppData\Local\Temp|*|RECURSE
FileKey4=%WinDir%\System32\config\systemprofile\AppData\Local\Temp|*|RECURSE
FileKey5=%WinDir%\System32\config\systemprofile\Local Settings\Temp|*|RECURSE
FileKey6=%WinDir%\SystemTemp|*|RECURSE
FileKey7=%WinDir%\SysWOW64\config\systemprofile\AppData\Local\Temp|*|RECURSE
And have run CCleaner several times and have been able to install applications without Error 2203.
Before Error 2203 would always come up and even after trying sfc /scannow, changing permissions and even doing a full Windows feature upgrade, I could not resolve the error.