Hi, I don't think there is a built-in option to simply disable Alt+Space. It will likely take a 3rd party app. I would use [
AutoHotKey]. Download it, install it, and open notepad. Type the following two lines in:
; Disable Alt+Space
!Space::Return
The first line is a comment and is optional. The 2nd line tells the program to catch Alt (!) and Space and do nothing once it catches it. Save the script as DisableKeys.ahk and save it to your desktop. You have to use the
.ahk extension. Double click on it to run it. You will see AutoHotKey in the tray (near clock). The key combination should now be disabled, so try it out. You can right click on the icon in the tray and close the script out at anytime. You can easily convert .ahk files to .exe files by right clicking on them and choosing compile script.
Other ideas:
https://www.howtogeek.com/194811/how-to-prevent-the-windows-key-alttab-and-sticky-keys-from-ruining-your-gaming/