I can't get Ultima Underworld to run.
 

I have XP and when I try running the game, the window pops up then closes after a split-second. can anyone help me out?

Run it in dosbox. (That's NOT XP dos window).
>A beginner's guide to DosBox<
>wtf IS dos bOX AND DOES IT WORK ON wIN xp?<
Yep.