BIOS Updates forum

Im running Windows XP Home and the problem is this. I start up my computer, it runs a memory check, changes screens as if it is going to change to the Windows loading screen, but at this point the screen turns black and only a white blinking cursor is in the top left of the screen. I can access BIOS, but I dont understand what happened. One minute my computer worked fine, now it wont even start up Any help would be much appreciated, thanks.