Just curious if there is a Windows XP Default Font, and if so, how do I change my system back to it?

Internet Explorer, AOL and even text within my games is now changed due to something changing my overall system font.  I have no idea what caused the change, I installed a couple drivers for a printer and joystick and also some Windows Updates, so it could have been any of those I am guessing.

At any rate, is there a way to change the overall font of my system?  It is affecting every application on my computer and I would really like to get it back to its default.  Thanks!

Matt