I wanted to add that looking through my task manager, I saw the mcupdate.exe was running a high CPU usage on my computer. My problem was that I have a cracked version of Vista Ultimate (from Dell) and it doesn't come with McAfee. I did a search on mcupdate, and of course it came up with the mcafee removal tool. I ran it, just out of curiosity, and after running it, with a reboot, the windows vista security center said that it couldn't find a A/V program.
I'll look into it further, and this might not be anyone else's problem, because I'm just foolin' around with a "fake" version of vista while I learn it, but it might have something to do with other's problems.
Just FYI i guess.