You can "biggefy" your display on Windows XP by holding down the Ctrl key and using the plus key or the mouse's scroll wheel to return it to its usual size. (It's very easy to shrink the display without knowing what you did so you can undo it.)
I don't have any experience with administration register. Does your computer have more than one user account? Usually the one with the authority to add or delete programs is a separate account called Administrator, and all other users have separate accounts with their own passwords. However, it's also possible to set up your computer with only one account, so the administrator is also the sole user, or so all the users are on the administrator account.
If you can reproduce one or more of these administrator messages, maybe someone far more technically adept than I can give you a hand.
Maryn, half-helpful
