To back up the registry:

1. Start -> Run -> regedit
2. Registry -> Export Registry File
3. Save the file somewhere

If you want to restore it, under the Registry menu click Import Registry File and browse to the file you saved.

But shouln't the cleaner be able to clean it up?
You're right, it should... Make sure it's up to date. Maybe you have to stop the process before you run it? I dunno.

I guess sometimes you just have to remove it manually. Do a search on your hard drive for aim.exe and delete the file if you find it. It will probably be in the system32 folder. That's where lots of trojans hide themselves. Good luck.

Oh, I guess I'd might as well give you this link as well. In case you didn't STFW

mjk