I guess first make sure they aren't in the startup folder ;P Next, MSconfig is a great utility that came with 98(and I think ME) If you have 2000 or XP, you could look for it on the net and download it. You get a couple errors because some files arn't used that MSConfig alters, but you still can change the startup settings.
Hijackthis is another program you can get if you REALLY want to clean things up, but you have to be careful what you delete...