I'm on Ubuntu 17.04. 5 years of muscle memory makes me hit ctrl-alt-delete then enter before walking away from my PC at work. On Ubuntu the default option that selects is restart. This has been a bit of a problem. How can I change it? I either want to remove the restart option or make the lock option primary. I looked around but cant find a way to do it.
For most desktops got to
control center or
Scroll through the list of preset shortcuts. You should find
Lock screen, and
shut down together.
Click on the one you want to change, then press the short cut to use.
In your case:
shut down then backspace to disable shut down.
Logout and press ctrl+alt+del to set it.