A: It's easy to convert a VHDX (the new format of VHD) to a VHD file in (formerly code-named Windows Server 8). Use the Edit Disk action within Hyper-V Manager. (See also,"Q: How can I convert a VHD to a VHDX?").
Select the VHDX file, then select the Convert option. In the Convert options screen, select VHD as the type, then continue with the rest of the conversion wizard and a VHD will be created (see screen shot below).
See more FAQs on virtualization, System Center, and all things IT pro at John Savill's FAQs.