Most of the above, plus, to "keep my computer running well" I use registry cleaners of various sorts. Although, I wouldn't recomend that to anyone who doesn't even know what the registry is...
Or, just go with Linux. You are instantly protected from the most common everythings...
--EDIT--
Oh, yeah. MissInfo. I can't see your computer, but they might be Windows Messenger windows. Try "shoot the messenger." (Put that into Google.) Or, find it under the Windows services and set it to disabled.