This is kind of a hidden windows program that will give a lot of info on what running and what not, and will allow you to turn them off and back on ( after a reboot ), it works with windows XP and maybe 2000.

Click start then go to "run" once open, type msconfig . This will open a systems file that will allow you to see what programs are loading up when you start your machine. Be careful what you turn off in the "Services tab" you may stop windows from running. you can shut down anything you want in the "Startup tab" this will only effect programs like your firewall, ad killer, Real player and stuff like that. Remember what you turn off so that you may turn it back on ( another reboot will be needed ). Also this program will sometime nag you on start up to run it again, if so check the box in the window of the nag and it will go away. You may be surprise to see how much junk you'll have in your "startup tab" .