Was messing around with my new Asus 242H monitor to get the colors looking pretty (which I did). Then I decided to start messing with the NVIDIA control panel for my GTX 460.
Background: My monitor is hooked up to my gcard via hdmi, vga, and dvi. I wanted to get my hdmi settings looking as pretty as my vga ones. Finally figured out how to do it, so I set my primary monitor as the hdmi one (it showed a monitor pic for each different connection in the nvidia control panel) and disabled the others. Then, in the diagram that shows your monitor configuration, I accidentally deleted the hdmi one! Scrolling through the inputs on my monitor gives me a black screen for both the dvi and vga with the message "no connection available" or something. On the hdmi input, the monitor displays a blue screen, and says the same thing.
I've tried rebooting, removing and reinserting the graphics card, and hooking up another monitor I had lying around via vga cable (it takes nothing but), and no luck.