Are WDM drivers compatible with both Windows 98 and Windows 2000?
If they’re designed to be, yes. In fact, that’s part of the definition: Rigorously speaking, a driver isn’t a “WDM driver” unless it has one driver binary that will run on both OSs. However, it is certainly possible to use some of the new WDM interfaces in a driver that won’t run on one of the two systems. Although both Windows 98 and Windows 2000 implement WDM, there are some significant differences, enough that it is possible to write a driver that uses the WDM interfaces and nevertheless works on one OS and not the other.
