This isn't specific to Windows Server Deployment, if that's what this forum is for, but I can't find a WDS-specific forum.
Anyway, here's the problem that I have:
I'm using the new "WIM2VHD" PowerShell (Convert-WindowsImage) script to convert some vanilla installs of Windows Client (8.1) to VHD's to make servicing them easier (mount to Hyper-V for online servicing). I'm using the standard conversion method of taking one of the stock Windows 8.1 Update ISO's and using the VHDX format with GPT partitioning for x64 and a max file size of an 8GB VHD. I do the same for the x86 ISO, but use MBR for that (because that's what Hyper-V supports).
When I try a VHDX deployment via WDS to a machine (physical or virtual), I get an error message saying that Windows Setup can't complete the setup procedure. When I look at the drive when the error is shown, I can see that Windows creates the 2 funny Windows Setup folders with the tilde (~BT and whatever the other one is - I forget) and a WindowsImages folder on the root. The VHDX file is copied over but nothing is done with it. I'm NOT trying to do a Native VHD boot though (I don't even have any scripts set up). I'd like to just extract the VHDX to the hard drive and go from there, which according to the TechNet docs is possible as it says WDS can treat VHD's like normal WIM files. So why is it not working this way?
Also, is it standard procedure for WDS to block GPT-formatted VHDX's from deployment to BIOS systems, and MBR-formatted VHDX's to UEFI systems? If I'm not using Native VHD Boot and want to just extract the image, why would WDS care what format the virtual hard drive is in if it's just going to extract everything to a different drive? Or is this handling of files due to something that is broken with the above (I would guess Native VHD Boot would require UEFI+GPT and BIOS+MBR)?