Hi, I have this Alienware M17X which was recently bought. An update was installed and Windows started acting funny. At first it wouldn't boot any more; and I couldn't do any Windows automatic repairs because the hard drive is locked. So I changed in the BIOS the SATA settings to AHCI as the Dell website suggests and now Windows boots fine. However, the desktop cannot be accessed. Whenever I go to the desktop or use the search function in Metro the screen flickers black and the computer freezes or logs me out. Because of this I cannot rollback the nVidia drivers (which I think are the cause). What can I do? Thanks in advance!