You could try a system restore if that doesn't help then you could try a system recovery. If either one of these does not fix you, I would suggest calling Asus tech support.
System Restore - Click Start, All programs, Accessories, System tools, here you will find the system restore.
System Recovery - If your laptop has the partition recovery option, start up your computer, tap F9 and follow the system recovery instructions. This will remove everything you installed on It and put it back like it was the day bought it. You will have to reinstall your games and programs after performing the system recovery.
Before trying the two options listed above are you trying to play your games at maximum settings? If you are, try lowering some settings, turn off antialising if you have it enabled and lower the screen resolution a little.