|vandal67, first thing I'd do is make sure there's no nasty causing it (virus, worm/trojan, etc.?). Be aware that a virus and a Trojan are similar, but not the same. Many times, an AV detects one it can't clean, other times, it gets missed entirely.|
If you need to clean one, Superantispyware (info only. I’m not paid for recommendation. WARNING! FYI, a full scan on mine takes over an hour.) can do the job and you can get it free @:
among other places. They have a Vista compatible version if needed. Dunno about Windows 7 or later.
If it turns out that you need to use it, be sure to update Superantispyware prior to running and disable 'restore' (restart after cleaning) so the nasty doesn't get put back. They just released a new update recently and it changes all the time. Things are in a constant state of flux.
The restore thing is critical. May not be your deal at all, but won't hurt anything to try.
Once you're sure you have a clean machine, find a list of 'musts' @:
make sure there're no xtras in your startup menu.
Ed in Texas.