How do I stop Norton Internet Security?

NIS is interfering with software I am running to try to remove the trojans and adware items that NIS cannot deal with. I have turned off and disabled everything I can find, but NIS still comes up with messages that indicate autoprotect is still working. I found the Norton process in Task Manager, but I was not allowed to stop it (which was a surprise, since I have administrator rights). Norton has been a disappointment in all this. It continually blocks the actions of infectious items but does not find or remove them, including the  extra strong erase scan.