Unfortunately a lot of shareware is not compatible with xp, because it's based on NT architecture. Unlike 9x which is based on DOS, and can run most if not all the shareware of the 90s.
Also XP was released in 2001, so not the best choice for 90s gaming. The lack of or limited compatibility, with 9x and DOS was an actual downside and reason not to upgrade for older hardware back in the day.