This post shows how to "make Alt + Space work!" For this post, "work" means "display the window menu" after installing PowerToys. I needed this to move windows with the keyboard after I had installed PowerToys.
Make Alt + Space work!: The Problem
If you see this pop-up when you type Alt + Space:
...instead of the window menu (aka system menu)...
...the problem is an Alt+Space keystroke collision with PowerToys Run and window menu display. To fix the collision, Disable PowerToys Run or change the PowerToys Run binding from Alt + Space to something else (Alt + Shift + Space).
Steps to Update PowerToys Run Shortcut, aka Binding
#1 Click PowerToys Run
#2 Change the shortcut from Alt+Space...
...to something else (like Alt + Shift + Space):
