Well I tried Googling around, and found nothing. I simply don't know what to do, so maybe one of you do.
Here's what I have.
An HP m7750n.
Vista basic.
And an Nvidia 8800 GTS 640mb.
Recently I tried restarting my computer, and as soon as I get to the desktop, this happens.

And then 5 seconds later, this.

I tried to back up my files to my external hard drive in safe mode, but it didn't work. Also I am unable to move my hard drive to another computer, and back up from there. So give me some advice.