Hyper-V does not work with Windows 10 Home. One needs the Pro edition, for which Microsoft conveniently supplies an upgrade button. Oh, you need $100, too. I was more worried about the fact that I only have the installation image that came with the computer as backup than the $100.
Virtual Box was suggested as an alternative, so I downloaded that. The two Windows features you turn on in Windows 10 to use Hyper-V, which you cannot use, need to be turned off. The instructions at Oracle (dot com!) suck, but it is the 21st century so the Intertubes are helpful.
I pulled a CentOS image from Linux VM Images (dot com!) because we use CentOS at work. It started up just fine. Note that you need to know the password, which is conveniently supplied on their site, mentioned the FAQ, and linked in the Settings dialog, but still seems to stymie some users, based on Intertube comments.
And it just went into some idle/power-save mode that I cannot get out of. Bye bye VM. I’ll figure that out, later. Next up: Install Docker.