The ALT key in Unity opens the Unity HUD (just try it outside of the game). It offers a search for every entry in the program menu. I'm not sure how to uninstall it, though. The HUD itself is contained in the package hud
, but removing it will likely give the alt key another function. But I'll show you how to change the shortcut.
Since I don't know what the English localization for the program needed for keyboard changes is called, I give you the terminal way (also graphical, just to start the application!)
Type in terminal:
gnome-control-center keyboard
- Click on the Shortcut tab.
- Find the section Starter and click on it.
- Change or delete the shortcut for calling the HUD (Standard: ALT L)
This should work for you. Remember the shortcut is (more or less?) global. So setting it to CTRL+S or CTRL+C or something like that would not be good.