I've been building VB software for more than 10 years (C, C++, Fortran, COBOL, AND PL/1 before that) and using Microsoft's Package and Deployment software to build distribution packages. Until this year I did all my work on NT and then Windows 2000. Never had a problem. This year I started working with XP. All of a sudden I discovered that when I tried to take a package put together on the XP machine and install it on a 2000 machine, I'd get the repeating "Setup cannot continue because some system files are out of date on your system" problem. I'm thoroughly familiar with the information at http://support.microsoft.com/kb/191096/EN-US/ and I've made sure everything is copacetic with that list of fixes, but the problem persists and I'm stumped.