If you're using H&R Block's TaxCut 2001 program with Windows XP, be prepared for a fatal error when you finalize your federal return. On the screen where it says "Congratulations, you've completed your Federal return...click Next to finish..." the program crashes and gives you an error message while the program collapses in the background. Now the funny part: It turns out that while TaxCut 2001 is marketed and sold as "100% Windows XP compatible," tech support advised me "it is not compatible with ALL Windows XP systems." When I asked what percentage of Windows XP systems TaxCut 2001 is compatible with, the tech rep paused a while and said "not many." The fix is--get this--to "make the program compatible with Windows 98 or earlier." [To do so, go to the Properties dialog (right click the TaxCut icon on the desktop) and select the "Compatibility" tab. There you can change the "compatibility" of the program to an earlier version of Windows (I recommend Win 3.1, based on their thorough testing program. )] What's really ironic is the program ran fine until I ran the mandatory TaxCut update to fix various bugs and incomplete(!) tax forms.