How to clean unnecessary process

Either by going to terminal services configuration panel, or open the manager, I realize that I have a lot of process. But it is annoying to know that there is a lot of things that are all alone without you. Especially since it takes a little extra time at startup. So is what you can safely remove some process? How to find if a process is not dangerous ? How do I know if a process is unnecessary and should be deleted ?

You can start by removing some programs at startup.

Go to Start, Run, msconfig, Startup tab, uncheck everything except your firewall and your antivirus (if other than XP) and your ISP connection software, Apply, OK, restart the computer, and check "Do not show this message "