Got inspired by this question to update my blog with a solution that I wrote a couple of years ago:
This script will enumerate through all devices on a machine and output the driver status:
You can see which drivers were used (or not used)
Alternatively I have user ZTIDrivers.log, just grep/findstr any line with the text "xcopy". The tool uses the xcopy.exe tool to actually copy the driver down to the local machine for install. If it performed an xcopy, the driver was copied. Note however that this does not necessarily mean that the OS used the driver copied down locally, the OS could decided that a different driver had a higher rank for use.
Keith Garner - keithga.wordpress.com