I have a post here addressing the same problem as before but I cannot find it.
The problem started a couple of months ago. Basically ud be working on the computer and for no reason the screen would go black and then flicker back and you'd get a message down the bottom stating the nvidia display driver
had failed but has now recovered.
Now the problem has got worse and now the screen goes out black and wont come back. This may be follow by a little blue box stating that there is is now HDMI input.
The only way out of this is to reset the pc and when it comes back it is ok for a while.
I have tried installing all video drivers
from the original disk and also downloading and installing the latest driver from the Nvidia web site.
I had some problem with some Physics driver in the package but think I have got that to go now.
This whole PC is less than 1yr old so I cant figure.
Any help appreciated