Download Driver sweeper, and run it in windows safe mode, let it scan and then delete all the drivers it finds.
But you know you dont have to delete previous drivers before updating.
Yes i know i don't have to remove old one for updating.
But when i try to update it still removes the previous one and then there also it stucks at "Removing Optimus"
And dude how to run windows 8 64bit in safe mode ?
I done trying F8 and Shift+F8 but windows 8 is opening i cant get into safe mode also :P