For months and months I've had my 2nd pc hooked up to a monitor and also my TV. I have a nvidia geforce gtx 460 that has two DVI ports in the back one goes to the monitor and the other to my TV. One day it just stopped recognizing it and when I go into windows settings the second display is nowhere to be found.
Will update my drivers tonight to see if it helps but since it was working for so long I don't anticipate that being the problem.
I also already replaced the DVI-HDMI cord with another one that still doesn't work.