The omnipotent Administrator

When you use Windows XP, you belong to one of two groups: Administrators or
Users. Administrators are all-powerful: if you have a so-called Admin account, you
can make systemwide changes and change other users' accounts. While this power is
a boon to the ego, it's also dangerous. If, for example, you encounter a virus, a
Trojan horse, or a worm while you're logged on as Administrator, you could wreck all
the accounts on your entire system. Log in as User, on the other hand, and any
damage you cause will be less extensive, because ordinary users are prevented from
making systemwide changes. A word to the wise: Do your everyday computing as a
regular user and log on as Administrator only when it's absolutely necessary, such as
when adding a new user or changing security settings. To sign on as User, use the
Run As command: just right-click a shortcut and select Run As. As long as you know
the username and password, you can sign on as another user.