Game will not expand to fit screen when rendered at sub-native resolution

[ThreeUnicornsInATrenchcoat]

I have a 1920x1080 screen. Normally, when I select 1280x720 as the game's resolution and play in fullscreen mode, the render window stretches to fit the entire screen. Now, the unused pixels outside the window are black, as though I am playing in windowed mode without being able to see the desktop in the background. The game window is surrounded by black bars, i.e. a vignette, but on both sides as well as top and bottom.

 

This issue arose after I toggled 2x2 supersampling through the NVIDIA Inspector tool. I have subsequently disabled supersampling, but the problem persists. I have reset all 3D render settings in both the NVIDIA Inspector and in the NVIDIA control panel. Neither reset fixed the problem.

 

The issue is not related to my load order, so I won't post that, but my relevant system specs are as follows:

 

ASUS ROG G74SX Notebook

Intel Core i7 2670QM @2.20 GHZ, OC'd to 3.0 GHz in high performance mode.

NVIDIA GeForce GTX 560M (2GiB VRAM, 192 CUDA cores, 775 MHz gpu clock, 1550 MHz shader clock, 1250 MHz memory clock)

GPU driver: GeForce 335.23 WHQL

1920x1080 native resolution, 32-bit color depth, 60Hz refresh rate.

 

I have not updated my drivers since the problem arose on June 13th. Wiping all of my driver profiles upon installing the latest GeForce driver package might fix the issue, but I am reluctant to do that for obvious reasons. I play in 720p most of the time because the lower resolution allows me to maintain a constant high framerate with 2x or 4x multisampling and a high mod count. I would appreciate insight from anyone who has experienced this problem.

 

EDIT 06-15 2:20 PM: Performing a fresh install of the GeForce 337.88 WHQL drivers failed to resolve the issue. In addition, the problem is present in Skyrim and Left 4 Dead 2, so it definitely isn't game-specific.

[ThreeUnicornsInATrenchcoat]

SOLVED.

 

Somehow, my display scaling setting was changed; I didn't do it myself.