Sorry bout that...
Windows has different versions / licensing for all it's software.
1) OEM: (like what you get with a DELL) is designed to be installed only onto one computer. Lic code in bios
2) Retail: You go into a store and buy a "retail box"
3) Development: Similar to retail only that you're supposed to use it for testing. Usually it will expire and stop working after a short period of time.
Regardless of which version you actually use, MS will generate an internal code number based on the chipset, bios, cpu, etc. That's why you can't just pull a windows hard disk from your laptop and plop it into your desktop (driver issues aside).
A RETAIL version supposedly has the tools to allow that to happen and will reconfigure itself. I personally have not verified this. Same for development versions. Fwiw, linux (generally) will let you do this.
The software that you use to create a virtual machine is called a hypervisor. KVM-QEMU, Virtualbox, VMware, Xen, etc. are all hypervisors. Qubes OS (https://www.qubes-os.org/
) is actually built around it (so everything you do there is inside virtual machines).
From the "inside" of a vm, the operating system sees virtual "hardware" just as it would see an actual physical system. Each hypervisor provides its own "motherboard, bios, graphics card, etc." And the differences between each hypervisor generate different windows "code numbers". Thus a copy of windows initially installed into virtualbox will likely fail when just copied over into qemu. Again, you supposedly can force it. I haven't played with it.
Without going further down the rabbit hole (unless you want to) I would personally just set up both virtual box and qemu and do clean installs into each. Let them just sit there and go "whirr" and do the update thing. Make backups and then start playing with each to see which one you like better. You may even find that some programs you use play better in one than the other, and so use both <shrug>.
Hope this helps