If you have a piece of software that refuses to install because it says that you are not running Windows 2000 (such as the Win2K drivers for a Mustek scanner!!) you can simply edit

HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows NT/CurrentVersion/ProductName

to say Microsoft Windows 2000 instead of XP and it will install. You may also have to edit the version number or build number, depending on how hard the program tries to verify that you are installing on the correct OS. I had to do this for my Mustek 600 CP scanner (compatibility mode didn't help!!!) and it worked great, so I now have my scanner working with XP (and a tech at Mustek can now eat his words). BTW, don't forget to restore any changes you make after you get your software installed.