It would definitely complicate things trying to run 2 windows installations. But I'm not. Up until I took a break from attempting to fix the issue, the hdd was completely detached. I switched them out and everything works as normal again.
I'd really like to try and get windows to boot from the ssd but I can always just use it as a drive to run any programs I want to, just not the OS.
I can confirm with pretty good confidence that the hdd used the legacy version of the media creation tool, way back at the release of windows 10. Could it be an issue where a drive using the legacy version but the uefi doesnt? This would be weird to me though considering the motherboard uses uefi and it is enabled. Is there a setting I'm missing that forces legacy mode only? I did also try installing on the ssd with the legacy media but it was not compatible. I even tried formatting the disk as MBR instead of GPT. A blank drive says it's just not compatible, when formatted as GPT it says it cannot because it isn't compatible with GPT. But when formatted as MBR it says it cannot install because of a MBR partition table. No matter what option I choose it isnt compatible with the legacy install media for some reason or the other. I can try mounting the iso again but I don't think it will work like last time.
It has to be a problem with the installer or the drive. But again the drive seems to work and the installer does too. The install media successfully runs. It seems like it missing a necessary file to boot windows or something. But then there are tons of files on the ssd, and I can also run other things from the ssd without issue. I can reformat it and use it as a second drive, just not a boot drive for some reason.
Could the board just not boot uefi type installations? The board is getting old, it was bought about 5 or 6 years ago now. The last firmware update was from 2014. Maybe the bios works with uefi but I'm forced to boot via legacy?