HOW do I disable second display/desktop

[fpsdf2]

I'd like to make a very simple use of Ubuntu on this laptop.

You see, on a fresh install, it is set up for this glitchy double display/desktop which makes the mouse cursor go beyond the right-hand edge of the desktop. The problem is I CAN'T SEE WHAT'S HAPPENING THERE! And I just can't seem to disable that feature and make it only make use of this laptop display. It's really been a problem, since a lot of windows/tools end up there, making some of my work impossible to deal with.

I thank you so much for your help!

[Holger_Gehrke]

Your post is a bit thin on information about your system. What make and model with what components, what version and flavour of Ubuntu ...

Take a look at this page in the official documentation (https://help.ubuntu.com/stable/ubuntu-help/display-dual-monitors.html.en) about multi-monitor displays especially the part about "Display Modes" "Single Display". This might help if you're using a current version of main line Ubuntu (and not some older version or another flavour) and if your OS for some reason assumes you've got a second display connected.

Holger