EFI Boot with ASROCK Z390M PRO4 MATX

[woodslanding]

I am trying to copy my old system over to a new machine built around the ASROCK Z390M PRO4 MATX motherboard. The old system used EFI boot. It's win10.

I have used Veeam 'clone to dissimilar hardware' option to clone the old system drive to the M.2 drive in the new machine. But I get an error:
OS Disk in Backup uses GPT Disk. This may cause boot issues.

and from their forums, it appears I need to set my BIOS to EFI boot.

Can anybody tell me how to do that? I am hoping this is possible, as I have fine-tuned the old system for a specific purpose, and really would like to be able to use it. But I have been through all the settings, and haven't found anything helpful.

Thanks!

[woodslanding]

Re: EFI Boot with ASROCK Z390M PRO4 MATX

I'm guessing this is because this was originally a windows 8 machine, which was upgraded. That's probably why it didn't have a UEFI setup. It does seem odd to me, because I seem to remember using UEFI to dual-boot my previous machine, a mac mini, without using bootcamp.

In any case, the more I read, the more confused I am getting. :(