Back in February, Microsoft introduced Hyper-V support for ARM64 PCs, something that was one of the key limitations at the time of Windows on ARM's launch. The only problem was that there was no way to actually spin up a Windows 10 virtual machine, because Microsoft doesn't make ARM64 images available.
Now, that's changing, at least for virtual machines. The firm released Windows 10 Insider Preview build 19624 as a VHDX for ARM64 PCs today, as the Windows Insider team teased yesterday. It probably goes without saying, but you cannot use this with x64 hardware.