I recently noticed that my desktop display feature appears to be locked. I'm able to get a wallpaper from online if i want, but cannot use any other options i.e browsing for pics within "my pictures" or selecting from the choices of already included desktop backgrounds. Even the options for "stretch, center, tile" are locked. I tried right-clicking a pic and selecting set as background and that didn't work. I also tried right clicking images then going through picture tasks, set as background - which also didn't work. I'm using Windows XP pro with service pack 2.

Silly question, but it's a starting point. Do you have privilages to do so? If you are using a PC that is controlled by another user, they may have restricted your privilages.

Also, try logging in as administrator and see if you are able to do so.

For a quick fix, you can open a picture in IE and use the "set as background" function. It's a good workaround while you try to resolve the issue.