There are a few ways to attack this. If there are services running that do not show up int the process list of Task Manager go to Start & Run and type in services.msc and click on OK.
Double click on any service that you do not want to run and select Disabled. The next time Windows starts that service will not start.
You can als go to start and run and type in msconfig and click on Ok. The last two tabs show services and applications that load at startup. Uncheck anything that you do not want running.
Wintasks Pro is a very good program that tells you what proccesses and threads are running and lets you stop them and start them at will.
It is made by LIUtilities