Compatible

Adoption of windows 7 depends on software developed to cope with it by makers of printers, networking equipment, cameras and other devices ------ drivers
How about percentage coverage of all the hardware drivers which are compatible with windows 7?

Putting a percentage on hardware compatability for Windows 7 depends on how many years of hardware you are comparing. Backwards compatability does have a stopping point. So how far back are you wanting to go. Personally I think Windows 7 is doing great with compatability.

P.S. This question is really premature until Released To Manufature(RTM) so the compatibility issues can be resolved.

I'm pretty much in agreement with what Clifford said - it depends on how far back you go (I've not found any recent hardware that has had problems). Some wireless adapters that are about 5 years old have caused problems for me, but perhaps that will change once W7 goes RTM.