Hi eversio, welcome to the forums.
Sorry to say, but this could have been caused by the upgrade.
You might want to try this though;
From the start menu, type cmd
, then right-click the result & choose 'Run as administrator' this will open it as elevated. Then type sfc /scannow
to run a system file integrity check, which will highlight any system file issues.
[note this process can take a bit of time (5-10 mins)[/note]
Hope this helps