The system in question was running a ASRock Taichi X470 with a Gigabyte RTX 2060 up until a few hours when I took out the 2060 to put into another PC, and replaced it with an ASUS Vega 56 Strix Card. The Vega 56 Card came out of a PC that had been sitting for a while, but I knew worked fine when it was last turned on.
Before removing the 2060 I ran DDU in safe mode, shut down the PC, popped in the Vega, booted up and went to download drivers. The driver installation failed in where the screen went black and never came back. I tried swapping ports and cables before killing the power as a last resort. Upon booting up again, everything that should have been black was green, from BIOS on into Windows, with lots of screen glitching along the ride. I restarted it into safe mode with networking, ran DDU again, and downloaded the specific drivers for the card instead of letting the Radeon Software decide for me. Rebooted into Windows (with my Ethernet Cable disconnected), now running default Windows drivers on 640x480, or whatever it defaults to, with no glitching or green.
With nothing in the C:/AMD folder left, I started a fresh install of 20.4.1, which is what it directed my to after choposing my card out from it's listings. Install went through without a hitch, but now we're back to glitchiness and artifacting, however this time without the green.
Currently sitting in Safe Mode right now, and would really like not to be. Where do I go from here..?
EDIT: Have also tried the 18.10.16 Version of Software from the ASUS Product Page to the same results
EDIT: Had to swap in an RX570 so I could use the PC again; but when taking out the Vega card, the metal back-plate almost burnt me on the way out. Never had it get that hot before.