We've got a question for home users of Windows XP:
How many of you use Windows XP limited accounts? Raise your hands.
Not surprisingly, the answer turns out to be "not many." Windows XP limited accounts were too, well, limited. Many applications simply didn't work properly under limited accounts, because application writers didn't follow the rules. The net result is that the vast majority of Windows XP users are system administrators. Running with administrator privileges is a root cause of many of XP's well-documented security woes.