gpedit.msc

Group policy is edited on a local per-machine level using the Group Policy Editor, or gpedit.msc (stick it in your Run box).

Computer Configuration \ Windows Settings \ Security Settings \ Software Restriction Policies \ Additional Rules

Right click and add a new path rule. Then disallow Edge's path. On the machine I'm sitting at it's c:\Program Files (x86)\Microsoft\Edge\Application.

Just disallow everything in there (*) and any time something tries to launch Edge in your face you'll get this:

Look at me. I am the administrator now.

If you are on a non-Pro version of Windows and don't have access to the Group Policy Editor, you can just use this which is considerably less hassle.