Well if you are running Windows XP
Go to Start > msconfig and hit enter or return which ever you have.
then click on the services tab these are the running processes on you computer just un tick the ones you don't want...ALSO click on the start up tab and un tick the ones you don't want to start when you reboot your computer.
Now this will prompt you to do a re-start just click yes to make sure all is good...If you some reason you it won't boot up you probably need to boot into safe mode and re tick the one(s) you un ticked.