When I went into Advanced settings the only option for secure boot was CSM or UEFI. I select UEFI and reboot. Windows
10 doesn't even start, just goes back to BIOS. I assume it's looking exclusively for UEFI drives which won't be there until
11 is installed.
Yes. Switching between those two BIOS modes
after you have already installed Windows will make the boot process fail at first.
You see, when Windows detects a BIOS in CSM/Legacy mode during installation, such as what was the case when you originally installed Windows 10, then it prepares the boot drive to have an MBR (Master Boot Record). When Windows detects a UEFI BIOS during installation, it will prepare the boot drive with a GPT (GUID partition table) instead.
The BIOS set to either mode (CSM/Legacy vs. UEFI) will only boot from a drive that was prepared accordingly for that mode (CSM/Legacy needs MBR, UEFI needs GPT). That's why you need to do a quick
MBR to GPT conversion for your boot drive before you can set your BIOS to UEFI mode, to be able to boot that Windows afterwards (you could also do a fresh install of Windows, but that's more work).
That conversion is not too difficult, it basically consists of two commands in the command prompt of the Windows Recovery Environment. And even that sounds more complicated than it ends up being.
What I would also strongly suggest though: Right after doing the conversion for the boot drive, don't just set the BIOS to UEFI mode, instead, do another step of updating the BIOS to the latest beta version from
https://www.msi.com/Motherboard/MPG-X570-GAMING-EDGE-WIFI/support
That will not only set things up properly in regards to UEFI mode as default, with Secure Boot and fTPM 2.0 enabled, but will also prevent future issues regarding these functions, by using updated implementations of them.
BIOS Update how-to:
1) Get the latest BIOS. It's the topmost one on the MSI support page for your board.
2) Extract the file and you will get a text file and the BIOS file. Put the BIOS file into the root folder of a USB stick/drive.
3) Enter the BIOS by pressing DEL during boot, go to "M-FLASH" in the BIOS.
4) Once M-Flash (the updater) is loaded, it will show a list of your drives. Select the USB stick and select the previously extracted BIOS file on there.
5) It will ask for confirmation and then update the BIOS. It's fully automatic from there, takes about two minutes.
So with these two steps: Convert MBR to GPT, and BIOS update to the latest beta version - everything should be solved.
