You can download Windows 10 directly from Microsoft. Any version you like, if you use the command line interface.
You can then use an open source bit of software to commercially license it. This is basically legitimate, for all intents and purposes. It’s how corporate licenses are done.
A computer built for Windows 11 hardware should work just fine in Windows 10. You might not be able to use the official manufacturer’s drivers for certain bits, but the generic drivers should still work.
You can download Windows 10 directly from Microsoft. Any version you like, if you use the command line interface.
You can then use an open source bit of software to commercially license it. This is basically legitimate, for all intents and purposes. It’s how corporate licenses are done.
A computer built for Windows 11 hardware should work just fine in Windows 10. You might not be able to use the official manufacturer’s drivers for certain bits, but the generic drivers should still work.