I believe the program you were looking for is winconfig. Just type that into the run box on your start menu and hit enter. It's been a while but I think the settings for all you start up items is to the far right. You can individually turn things off and on. Be careful not to turn too much off. A general rule of thumb is that it's pretty safe to turn off most anything that is located somewhere below Program Files.

Another thing could be your hard drive going south. In the last few years I have had two go out on me. The first sign was the computer just started to run very slowly. This would not be a bad time to back up your personal files, just in case. Good luck!

William
KD0IJA