Windows 7, installed as service.
Have a separate Administrator user, got asked for the password.
But then ...
Extracting files to "C:\Program Files\Process Lasso" folder
Extracting from pl4sfx.exe
Cannot create ProcessGovernor.exe
Cannot create pl_rsrc_english.dll
Then it doesn't finalize, seems to become stuck. Is giving this output message and no further progress:
Extracting QuickUpgrade.exe.Replacement
The upgrade which came in just by today ...
Were you updating from a recent beta or the last final version? That will help narrow down on the likely cause of the failure.
In the interim, you should run the full installer again to ensure version consistency of files. No need to uninstall first, just run it over-top.