Is there a way to force the original 4:3 aspect ratio? My display runs at 1920x1080 native. When I choose the highest resolution of 1024x768 the image is stretched. I'd prefer black bars left and right.

Thanks for any help!

EDIT: I changed my nvidia settings and how the graphic card handles different aspect ratios. I didn't know about this at first. Works fine for me now :)

Did you try forcing it via your GPU control center/panel?
For AMD cards, look for Image scaling and then choose Maintain aspect ratio.
For Nvidia cards - Scaling > Aspect ratio.

Funny, I just found it in my nvidia settings :) Works great. Thanks for your help anyways :)