Boot configuration data missing, no EFI partition, non-GPT disk

Use bcdboot to rebuild the contents of the system partition. It will copy the static Windows Boot Manager files from the specified Windows installation and will build a new BCD (or update an existing one).

bcdboot /v c:\windows

If it doesn't detect the system partition automatically, you can use the /s option to specify it by drive letter. For more steps see this other thread about creating a system partition from scratch.

Note that "System Reserved" is just the partition's label, it doesn't indicate anything about whether the partition is valid or not.

Regarding fresh installation, Windows' requirements depend purely on which mode the install medium itself was booted in. If the USB stick was booted in UEFI mode (or if you used e.g. Rufus to create an "UEFI-only" USB stick), it will install the OS for UEFI mode and will require GPT disk for that. And if it was booted in legacy mode, it will expect a MBR disk and will install for legacy mode as well.