I have Ubuntu 16.04 running. It was working fine until I tried to load Windows onto a partition. I had to quit because I needed to format one of my drives which I had some important files on. When I switched back to ubuntu, my screen resolution was set to 4:3 instead of 16:9 and when I clicked 'display' I could not set it back, as 4:3 was the only option available. How do I revert back to 16:9?

Also, when I run sudo xrandr -q, I get the following error:

xrandr: Failed to get size of gamma for output default


It seems that you need to add the resolution mode, you can check it here:


or here if that doesn't works:


  • None of these solutions work because every time I run the xrandr command, I get the same error as before. – user1470463 Jul 27 '17 at 16:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.