It was a couple of months ago, so I don't recall exactly, but I think I couldn't get it to recognise the hard disk.

Are you using any particular boot settings, and are you using IDE or SCSI (virtual) disks?

I think that we use blkvsc and storvsc disks. I think that the former are used for boot.

I am currently running it with as far as I remember standard setting in Hyper-V, so it may have been some sperious error that happened to you.

I remember having issues with the default Ethernet-adapter, but getting it booted was never an issue.

Maybe OP is misremembering his issues?