Almost nothing runs on pure DOS these days, that's why the "original" X-Wing is hard to come by. However, if you have Windows XP (or even Win2K Pro w/ the latest service pack and DirectX), you can try running either the X-Wing Collectors' Series or the X-Wing Trilogy version of X-Wing in "compatibility mode". Either of these will have TIE Fighter, as well, and both games use the X-Wing vs. TIE Fighter graphics engine. Both games might also include X-Wing vs. TIE Fighter: Flight School, but that is useless if you want to play multiplayer over the Internet. The "Trilogy" package also includes X-Wing Alliance, which I'm sure you'll love if you get around to trying it.