Windows 7 Problem With Laptop Keyboard (Asus, Windows 7)

Hi! I just upgraded my laptop to windows 7. It is asus k50IN and it is claimed that it is compatible to windows 7 as stated in the asus site. However, there are some keys that do not function as before e.g. escape key and function key. There are applications that I cannot exit from fullscreen by hitting escape key. Is there any solution to this? thanks