I added an existing .VHD (XP SP3 guest OS, which I originally created in Virtual PC 2007 running on an XP SP3 host OS) to Hyper-V via the Hyper-V Manager. It worked fine, except, I have no "Insert Integration Services Setup Disk" option in the Action menu, so I have no video, sound, or network drivers in the guest OS. I've already uninstalled the Virtual Machine Additions package from the guest OS (which is Virtual PC's version of Hyper-V Integration Services), rebooted, as well as deleted and reattached the .VHD from Hyper-V Manager several times, to no avail. There is no VMGUEST.ISO file in my Windows 10 System32 folder either, so I can't attach it to the guest OS's virtual DVD drive manually.
I wish I could just have Virtual PC back. Even if I weren't having this particular issue, Hyper-V looks like a downgrade to me, at least with regard to what I use a virtual machine for. Virtual PC's keyboard shortcuts are better, the shutdown options are better, and the methods of attaching disc images are better. Hyper-V does seem to have plenty of powerful features that Virtual PC doesn't have, none of which I care about though. I only use a virtual machine as a sandboxed test bed for potentially malicious software and websites, and once I have the guest OS configured the way I want it, I always revert it back to that clean state when I'm finished. Virtual PC was perfect for this, and I doubt highly that there is any real reason why it can't run on Windows 10. In fact, I read a forum post where someone upgraded from Windows 7 (which they had Virtual PC installed on) to Windows 8, and Virtual PC continued to work fine. However, when you try to install Virtual PC on Windows 8, you get the same 0x80096002 error that you get when you try to install it on Windows 10, which tells me that Microsoft is just being belligerent; i.e., arbitrarily blocking the installation on Windows 8 and 10 just to irritate people.