How to transfer my Windows 10 Pro license?

thanks for clarification, NavyLCDR.

Made assumption from what I've read about it.. Assumptions usually don't work well with MS.

You will most definitely have room for another partition on a 1TB M.2

Partition Wizard is the King

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I've tried this on multiple occasions on multiple devices. De-activated the Windows 10 installation on one device, turned the device off.

Installed Win 10 on another device, used the key, activated.

Turned the "old" device back on and the installation is re-activated with the same key.

And many are still running smoothly, in tandem.

I don't think MS really cares.

EDIT : In all cases, these have been legitimately purchased, valid, genuine retail license keys - not $2 purchases on-line from eBay or Amazon or the like. Those ones, MS will identify eventually and block/de-activate on their server.

They don`t.