In windowsXP you can 1)start 2)search 3) all files and folders - all or part of the file name {type in what type of file your loking for ie *.mp3}, a word or phrase in the file - self explanatory -, look in - local hard drives -

That should locate any of the file types or phrases you searched for and return a location.

Just as thought you can check your recycle bin just in case they were deleted and sent there. If they are you can restore those files.

I'm not certain if a system restore to a previous point would recover the files or not. That is mainly used when you have installed an application, and it isn't working properly. What it does is basicaly rolls back the registry entries.

Or in the worst case you can "google" for undelete software.