If you get such a "recent" DOS games working well under XP, then well done, I can't even get Doom2 working under XP on my PC at a decent speed, that plays at like 20% the normal speed or something It's because DOS is emulated under XP and doesn't really exist, so many of the things these older games expect to have are no longer supported.

One of the reasons why a dual boot sytem between XP and an older version of Windows may be useful