Cannot change desktop background

If you are unable to backup any files that you want to keep, then you should do a custom install instead of a clean install. A custom install is just like a clean install, but will have a C:\Windows.old folder with a copy of all of your current installation files in it when the new installation is complete.

zmturner said:

Brink,
Why won't "regedit" work? I think if i could get into i might be able to fix the wallpaper issue.

It's starting to sound like you may have been infected with some sort of malware or virus with not being able to change your background or open regedit.

What does it do when you try to open regedit? Any error messages?

You might see if you can enable regedit using this.

Regedit - Enable or Disable - Vista Forums

That's great new Zmturner. I'm happy to hear that you got it sorted. :)