Here's all that went wrong:
-Nvidia driver not compatible with Blender.
-Upgrade driver and lose graphics entirely.
-Downgrade driver and still have no graphics.
-Futile troubleshooting and frustrated googling.
-Try to boot from USB, MSI fastboot blocking all preboot USB.
-More googling...
-Take computer completely apart to get to BIOS battery.
-Reset BIOS
-Put computer back together.
-Turn of Windows defaults in BIOS.
-Boot to USB.
-Back up home folder to USB hard drive (ongoing)
To-do:
-Install Pop-OS.
-Install Drivers, software, and custom user config.
-Restore Steam library.
-Test everything to make sure things still work the way I like them.