To follow up on Eee's case for future reference, after more communication with Eee it was discovered that their attempt to install the drivers by copying them directly to the /inf folder broke the windows update mechanism on Windows 8.
Symptoms:
-Attempting to install a driver via windows update resulted in an error dialog "error 2 system cannot find the file specified"
-Setupapi.dev.log shows install failure with the error "!!! ndv: Driver package import failed for device."
-But, windows update logs show driver was matched and downloaded succesfully
Cause:
-A copy of the driver inf file was being programatically copied directly into the %windir%\inf folder by an application installer (Windows 7 works correctly in this case, Windows 8 fails as described above).
Resolution:
-Remove the copied inf file from the computer, remove the device, reboot, reinsert the device and allow windows update to successfully install the driver.
Note: installers should never directly copy files to the \inf folder. The correct method to add drivers is to add them to the driver store using pnputil or the driver API.