Agree with rolli59. Try uninstalling/re-installing in safe mode. Can't hurt to run Driver Sweeper too. It'll clean up all the left over stuff from driver installations to make sure it's a clean install. http://phyxion.net/item/driver-sweeper.html
Yes, before I post his thread, I have already downloaded the Driver Sweeper v3.2.0, and in safe mode, I selected display and analyse and then cleaned them all. right now if I run Driver Sweeper again, there is no more files can be found in Nvida or AMD display option, they are all cleared.
My system is win7 sp1, and I think is up to date already ,checked in the Updates already.