its probably because of a corrupt driver description file a .ini file i believe. I would need to known your chipset to give more precise instructions; but your next step should be looking up what .ini files have the graphics device descriptors in them. they will need to be deleted. So what i would do is this, in this spicific order. Do a CLEAN Remove of current drivers again ( don't reinstall yet, it will be last) Then you want to delete the graphics hardware descriptor files. Reboot, Then I would suggest you install the latest systemboard/chipset drivers again. REBOOT again. Then do the system update and see if it fills any missing files. and Very Lastly, reinstall the video drivers. ---
But the biggest thing is needing to get rid of the INF or INI files that identify device information for the graphics card. Then get some good versions installed. I don't recall the link, but there is a few instructions out there on how to find what device descriptor files need to be deleted. ( and as always, backup those files or move them before you delete.) I hope this help. And the order of operation is very important.