I've been running into a problem lately with my dell laptop (windows 8.1). I updated my graphics driver using the nvidia software and got a black screen after start up and can't access the desktop.
After trying many of the repair options, I found I could get it working if I "refreshed" windows. I guess this removes all driver updates because my graphics were worse than ever. I tried updating the driver again and had the same problem, used a system restore point this time. I tried updating again, manually this time, and it worked. I think I somehow did it without restarting.
Today my computer restarted unexpectedly and now it wont boot up again. I'd love to know what's likely wrong with it (graphics card failure?) but I'd especially like to know if there's a way to work around this problem - as it was working for days before the restart I have to wonder if that's possible. My warranty also just expired, of course.
I suggest you try to start in "safe mode" by using the F8 key after you see the Windows logo. This will start the computer graphics in VGA mode. If this works then you can see about reverting the video driver to the last working one. Then you can change the option to automatically apply Windows updates so that you approve each one. Then never approve a video driver update. It's possible the Microsoft provided driver is incompatible with the hardware you have. If you download a video driver from the manufactures web site then is should work OK.