Your OS (Linux, Mac, Windows)
Windows 10

Your version of Opera
72.0.3815.459 (GX)
73.0.3856.284 (Base)

A screen-shot of the problem if it's related to something not showing as should
N/A, I'm not fast enough on the draw to catch the window and it's just a white square anyway

A description of the problem, including as much as information as possible
I have a fresh computer with Windows 10 and a fresh install of Opera, unused and unaltered because of this problem. My previous computer on 8.1 used GX fine.
When I open either Opera or Opera GX, the window flashes up onscreen and closes instantly. If I open more than one tab at once, it works for a few seconds, but repeatedly gives the usual popup asking if I'm sure I'd like to close with multiple tabs, then eventually goes ahead and closes anyway.
Uninstalled McAfee, disabled real-time protection and firewall on Windows Defender, ran the installer again, no success
Could this be related to Microsoft Family Features? It's giving popups and restricting me I try Chrome and Firefox

Steps to (try to) reproduce the issue
Use a fresh computer with Windows 10, download Opera or Opera GX, try to run either of them

Expected behavior and actual one
-Opera or Opera GX remain open when executed
-Opera and Opera GX do not remain open when executed