Issues Installing windows to new VHD on existing drive [MBR | GUID Partition Table]

I managed to contig and shrink my windows 10 install on c: and I have some room, not yet enough room (if 64GB required).

I'm trying the windows 11 tiny, or trying to! Stuck with install to vhd on bare metal (been a while since I did with windows 7, on MBR with bcdboot fun).

I've just discovered mbr2gpt, but that fails to validate.

Also I'm just looking in disk-management, and whilst the USB is MBR, the disk is reportedly GPT

I thought it was reportedly MBR, and GPT was required. I got a warning like "the selected disk has an MBR partition table" (copied from Fix 'Windows Cannot Be Installed to This Disk MBR'.)

Doesn't look like I can edit my original, just wanted to add some details.

Tried creating an efi partition, both on the host physical drive (where the vhdx will reside) and then within the vhdx, and then tried both, only the first worked.

The install error is Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks.

I also tried mbr2gpt on the vhd disk once created and attached, alas this didn't work.

Delete all the existing partitions on the VHD and install it to a completely unallocated disk.