Windows XP Administrative Tools

Answer on 1 question:
Greetings,
I have played with system policy editor, which was not quite a good idea 😉
The result:
Several Windows XP Pro Machines have:
1. Administrative Tools Icon not functioning anymore (it opens empty folder or does not open at all)
2. Several Roaming users and even Network administrator with a local profile on those machines have Temporary internet Folder Size 0Mb and no location specified with no chance to change it, unless You do not copy Local Settings, andit disappears again after logout.
Network Administrator has 596mb initial which goes to 0 accidentally…
Maybe, there is a way to delete and restore Default User?
Thanks
David