Get DOS Box, it's an emulator for DOS. I know only of it's existance, however, as I have never used it. But, is this program graphical? Or does it just run the from CMD/DOS window in XP?
Just out of curiousity, does it use 100% of your CPU? I have a DOS DASIC editor called QBASIC (I think) and it uses all it can get. The only program I made with it did that too...