I've seen a lot of posts on the internet about a black screen after a reboot. My problem is similar but it happens after I lock windows (Win->L). I get a black screen and can see/move the mouse cursor around but cannot ever get the login screen again. Crtl-Alt-Delete does nothing. I end up having to do a hard reboot. I'm running Vista Ultimate 64 on an ASUS p6t board. I've checked the event logs and there is nothing before the hard reboot. Any ideas?