Hi, I have a Dell Studio 1569 that's a few years old running Windows 7. Yesterday I had a problem I've never seen before with it, and I haven't been able to find this problem online. When I boot the computer, I see the bios load (the Dell icon screen), and then Windows starts to load as normal (the screen with the Windows Flag icon). As soon as Windows finishes loading, when I normally get a cursor and the account login screen, however, the screen shuts off, although I do still hear the normal sound it makes when it's finished booting up and displaying the login screen. The backlight is off too, it's not just blank. This first happened while I was just using the computer as normal, with an external monitor, and it affected both the built-in screen and the external monitor and has persisted on rebooting whether or not the external monitor is plugged in. If I interrupt the bios and run video diagnostics they do not report any errors; if I interrupt the boot to boot Windows in safe mode the computer works as normal (haven't been able to test the external monitor since safe mode doesn't seem to be compatible with it). This makes me suspect a software, rather than hardware problem (if it actually is a hardware problem this can be moved to the correct forum), but I'm not sure how to resolve it either in the bios or once I've booted into safe mode. I've already tried performing a Windows system restore to a time before the problem started and resetting to the last good configuration; neither has resulted in any changes. Any suggestions?