Geforce GTX560 suddenly only displays 800x600 resolution

I was working on my desktop computer normally like any other day when the monitor suddenly went on standby and wouldn't turn back on (like the light went orange and wouldn't turn green again). I unplugged and re-plugged the monitor cables and nothing happened. Then I proceeded to restart my computer by pressing power button and holding it for like 5 seconds and then releasing it. When the computer restarted it's resolution was 800x600 resolution compared to the 1920x1080 that I had always had prior to the restart. I right clicked the desktop and tried to change it to its old resolution the regular way but only the 800x600 option was available. So I went to the NVIDIA icon in the system tray and clicked it because I thought that maybe I needed to update the graphics card driver or something (BTW I have NVIDIA 560 graphics card) but when I clicked the icon it told me no NVIDIA card was detected which is strange so I went and uninstalled the NVIDIA driver and re-downloaded it and re-installed it but nothing it still tells me that the NVIDIA video card isn't detected. So I opened my computer case and checked to see if I could switch my computer to a different port and so I did but it also didn't do fix it and I got the same results. I thought the card had just died but then I noticed that the fan is still spinning and I don't have a ONBOARD graphics card So if the card is fried or dead how is it possible that I am still getting a display? and if it's not the why is it working like this (only 800x600 display?) and what could the cause of the problem if it's not the videocard itself?