I believe that a defence of Chen’s nomenclature can be constructed, but I agree with you that it probably isn’t a major security bug (and this hasn’t really been raised on his blog).

Windows 2003 Server refuses to provide an easy way out because it’s a -server- operating system. It’s supposed to be -stable-. “Sure guys, just go ahead and install any old kernel-mode stuff you want to.”

I guess the WHQL stuff is a bit like the taint warnings on Linux kernels – a ‘You have been warned’ step.

As to fixing it, I assume you’ve checked System Properties (Hardware -> Driver Signing) for this sort of thing. If that doesn’t work, devcon (from Microsoft) might be worth a shot – issuing a devcon update command generally overrides all sanity checks.