Also, he did tell me one time years ago that the windows based computers would see some of the DOS files as corrupt and try to fix them automatically and cause numerous problems with the program and recommended not having windows on the Dyno's computer. I know it's high but the best money we spent was changing over to the Performance Trends software. The Dyno is a really good piece and very accurate but with no support on the software and having to use older computers to run it, it just became too much of a hassle. Good Luck!