XP has no dos and while many old dos games will run on it you often have to run with no sound while others wont rua at all.
first try DOSBOX a freeware dos emulator for XP
http://dosbox.sourceforge.net/news.php?show_news=1
this neat litte prog not only runs the games but emulates several sound cards as well ( i use soundblaster16 for best results) so you get sound from onboard soundcards found on most modern boards.
it will even run games of a CD
it saved me a lot of frustration and enabled me enjoy some of my old sofware and all those abandonware games now available on the net