preserving 4:3 aspect ratio on a widescreen monitor?

[indiarubber]

most monitors default to stretching the image unless a game/program is specifically designed to preserve aspect ratio, but shouldn't it be simple to circumvent this? i own an AOC F22 1080p monitor with few picture customization options and don't see a way to do it natively, but are there other options i can look into?

edit: i'm running an nvida gtx260 and the control panel's scaling options aren't exactly straight forward. i'm gonna try experimenting, but any help there is appreciated if it's an adequate solution

edit 2: on second thought, that was pretty straightforward. now for the last question: is there any hit to image quality or performance for a standard 1920x1080 image when using gpu scaling as opposed to monitor scaling? i suppose if i'm worried about that i can set scaling options on a case by case basis, leaving monitor scaling as the default, but it'd certainly be simpler the other way

[The_cranky_hermit]

GPU scaling with an nVidia card is as good as it's going to get, really. The quality of monitor scaling depends on the monitor, but no matter how good your monitor is at scaling, you're better off with GPU scaling.

The performance requirement for GPU scaling is negligible. I would be surprised if you could even measure it.