How do I resolve desktop larger than screen?

NOTE: I'm answering this question because it is the first result that appears in a google search.

I had this same problem and I spent ages searching for a way to fix it within Ubuntu to no avail.

Turns out though that it can be solved by looking at the settings of the monitor/TV you are using. Not the Ubuntu settings, the actual built-in settings for the display that you access by pressing the physical buttons on the display.

For me I had to change the aspect ratio settings from 16:9 to "Just Scan". Not sure what it means, but it did the job.

Also had xrandr -q report larger resolution than my display could give:

# xrandr -q
Screen 0: minimum 320 x 200, current 1366 x 1024, maximum 8192 x 8192
LVDS1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
   1366x768      60.00*+
...

This command solved the problem:

xrandr --size 1366x768