2) Your driver. In the Nvidia control panel, look for "Adjust desktop size and position" and try "No scaling". I think that "GPU" has to be selected under "Perform scaling on..." for this to work.
Currently, I do not have such an option available under that heading. Here is some additional info I posted in the Nvidia forums:
Recently whenever I played a game that had a lower resolution, it would display at that resolution surrounded by black bars. Everything was great. I had then tried to add 640x480 as a supported resolution by going to the Nvidia control panel -> Change Resolution -> 2. Apply the following settings -> clicking the "Customize" button and checking the boxes for each 640x480 setting. Later I undid those checks to remove them from the list in the box labeled "Resolution:".
However, now I noticed that the games that maintained their aspect ratio before now skew and stretch to display at the full 1920x1080.
I also do not have the option to select the type of scaling under "Adjust desktop size and postion", as it only has "2. When my desktop is displayed on my HDTV". I also noticed that while 640x480 is no longer in the "Resolution:" box, the 640x480 options are also no longer selectable from the "Customize" list.
From a couple of responses they suggested trying to set the res to a non-native one in the control panel, then reopen the control panel (or even reboot first) and that should make the option appear.
I will try that tonight and see what happens. Out of curiosity, what is really the difference between the "HD, SD" and "PC"? Is it simple the set of resolutions available? Why would Nvidia think my monitor is an HDTV and not a monitor? Possibly because my drivers are old?
Thanks for the help, as usual!