Rylex has been experimenting with a DOS emulator for Windows XP entitled Abandon Loader. While MyJemm exists to help people play Privateer and Armada in Windows 9x, Windows XP users have been trying a variety of different methods with varying degrees of success. A program we mentioned earlier, VDMSound, is also linked from the Abandon Loader page. In conjunction, the two should help you get some of the older games running smoothly again.
I've found another great tool called "Abandon Loader" that is able to play old WC-games even in Windows XP and even with joystick and sound. I've been able to play WC1 with sound and joystick support! (and yeah this tool even allows you to slow your system down for older games) This is a tool that allows you to play nearly all old DOS-games under Windows XP. It requires some time to find your way how it works but I think you definitely should take a look at this one! You'll need the normal package, and please install the VDM-Sound BEFORE (!!!) the Abandon Loader. I hope this helps you bit ;-)You can grab Abandon Loader here. If you have any problems, head on over to Crius.net for help. And if this version doesn't support certain games such as Privateer, the next version is expected to have enhanced memory fixes.