Repair/reset user permissions

WinXP Home SP2.... this PC had an error on startup: missing or corrupt system32\config file. I was able to get the PC to load to the desktop after a bit of work, but the permissions seem to be messed up. For example, if I try to run Notepad, I get an error that I do not have the appropriate permissions; but if I right click the Notepad shortcut, select "Run as...." and click OK in the "Run as...." window that opens, Notepad will run just fine. Then if I try to save a Notepad .txt file, I get another error about not being able to save it due to permissions. With the "Run as...", when the window opens, I make no changes at all; the top user is checked by default, and I just click OK, and the app will launch.
So, the question is: how do I repair/rebuild/reset the user permissions so that I can launch apps and save docs normally?
Thanks.

 

A quick test is create a new user account & try that out. If that works, your account is screwed. You might want to move all the files to that new account.

 

Problem solved.... it turns out that the owner of said PC didn't have any data he wanted saved and we just wiped it and reloaded XP. It seemed like the easiest, quickest, most surefire way to deal with it.... thanks for the suggestions though... I'll try to remember 'em for next time.