Hehe, disregard what I said about '.sys was mostly used for windows earlier then XP'. It's been a while since I digged into this. But I did suppress the .sys warnings because of the million warnings in the driverpacks. Like I said before, a lot of .inf files are very badly written. How some of them work, I still don't know. If I remember correctly, on the msdn site it said somewhere the .inf files need a SourceDiskFiles section. DrvComp only looks into this SourceDiskFiles section. It is impossible to add all the exceptions by hand for the badly written .inf files. So if you need to compress other drivers, copy them by hand to the destination folder and DrvComp will still compress them for you.