Control Issue

I have a friend that has a strange issue.
His computer works well except for the part where he would like to change his appearance.
If he right clicks on the main screen and in the drop-down menu goes to "Properties", there is no response.
Same if he goes to Control Panel and goes to Appearance & Themes, he cannot get any response from any action he wants to take there.
It blinks for a second, then nothing.
Every other function in Control Panel and on the desktop works fine,
just that issue does not function correctly.
Is there a missing .dll or something else I can not see that is preventing him from completing the task?
Any help is appreciated..:)

Sounds like a Registry cleaner was used or AV that had a false positive, maybe they removed something that should'nt have been.

System Restore or XP Repair would be my choice unless there's a backup from a program that removed something.