If it is restarting itself, then it sounds like malware. If it was a critical system process (which I don't beleive it is) then it wouldn't let you kill it. That and you'd probably recognize the name.

Which spyware removers did you try? Were they updated to the latest definitions?

Can you post a hijackthis log file so we can see more about the system?

You can download it from http://216.180.233.162/~merijn/files/HijackThis.exe
If you can't get it on your computer, then use another one.

Do you have this problem with multiple browsers? What browser are you using? What service pack level and patches have been applied? (Hint: Click on "help" then "about" in your browser to give us the info we need.) What operating system and service pack/patch level?