So, it still won't boot.
Secure Boot was disabled already.
There is this weird function in the BIOS I've never seen before that appears as the following:
Settings\Advanced\Windows OS Configuration
Windows 8.1/10 WHQL Support - Disabled
Windows 7 Installation - Enabled
MSI Fast Boot - Disabled
Fast Boot - Disabled
> Internal GOP Configuration
> Secure Boot
That's the entire menu. It appears that Windows 7 Installation was enabled while I was installing Arch. I can't imagine that would cause an issue, but I am not sure.
I presume that's a driver type of thing for installation because the info box for the Windows 7 Installation says the following:
Only for Windows 7 installation process.
The Windows 8.1/10 WHQL Support has the following for it's info box:
Enables the supports for Windows 8.1/10 or disables for other operating Systems.
Gonna try updating the BIOS after I try and disable both those Windows options and see if that makes it work. It's just confusing to me because the SSD doesn't appear in the boot options at all. It appears as being installed though in the BIOS. Though I guess that makes sense.
If I disable both Windows options, Secure Boot disappears entirely. That's a bit confusing because it implies Secure Boot is on even when it says "disabled" to me if it appears like that. Though I guess it also makes sense that it would only be usable when you were intending to boot Windows in general.
I can't seem to find the place where I would re-order the HDDs boot order themselves. Like, not "boot USB HDD -> UEFI HDD -> Legacy HDD" but where I say "use M.2 SSD as UEFI HDD instead of Seagate 2TB HDD".