My ASRock Intel Arc A380 does not want to work with my board

[brave otter]

Specs:
Intel Core i3-8100
2x8GB Corsair Vengeance LPX DDR4 @2400MHz
MSI H310M Pro-VLH Plus

What's Happening:

• The GPU is displaying an underscore
• The motherboard is showing a VGA error

Other:

• The GPU worked before a BIOS update that had support for Resizable BAR
• Putting the old BIOS on did not fix the issue

[eternal atlas]

Did you try clearing your CMOS and reseating the card?

[brave otter]

Yep

[eternal atlas]

Motherboard BIOS flashed to the latest revision as well?

[brave otter]

I flashed it to the latest version to try and get ReBAR but that didn't work, so I put the old one back because of my install of Windows being legacy

[eternal atlas]

I would honestly recommend you get a different flashdrive, format it correctly and use it to flash the mobo to the latest BIOS one more time.

Once you've done that, use the integrated graphics of your motherboard to boot into the OS, run a DDU to completely clean the drivers off from your system.
Put the card back in and see if the system is able to get into Windows again.

[brave otter]

I can't get into Windows with UEFI/CSM, is there a way to change that first?

[eternal atlas]

Hold on... Does your drive show up in BIOS at all?

[brave otter]

It shows up when set to Legacy, otherwise the whole boot order is UEFI stuff

[eternal atlas]

Does it boot with Legacy?

Because from what you're telling it would seem that you're still using a legacy OS in your system, when you updated the BIOS it reset the settings and took it off from Legacy mode.

[brave otter]

It boots with Legacy, the updated version only lets me use CSM or UEFI

[eternal atlas]

Set it to CSM and disable resize bar

It should allow you to boot into the OS

[brave otter]

I don't even have resize bar in the first place

[eternal atlas]

It should be somewhere in the BIOS, it might also be called SAM or Smart Access Memory instead.

Because if you're unable to find it, the alternative is to reinstall the entire operating system in GPT so you get UEFI support.