O.K. I've been hacking at this for three days straight, with no luck. I've already searched these forums, but haven't found anything truly helpful. I've got an OpenGL based program that runs fine in win98SE but has an error on Windows XP Pro. I've heard that older games (games made before 2000) have problems on XP, and I know certain new games only run on 2000 and XP. Exactly what is done differently at the development level to make software require XP, and how can software run on both older and newer versions of Windows? Basically, are there extra/updated files that are needed to adequately create an opengl program that will run in XP? I'm using an old compiler, Borland C++ 5.02, but I've never heard of this compiler having compatibility issues. Any help would be appreciated.