<p>I had an issue in the past were I upgraded a full retail version of Windows 7 to Windows 10, I then built a new computer and moved the retail Windows 7 to it without issue but I was no longer able to activate Windows 10 on it. I can’t remember the exact message but it was something along the lines that the free upgrade to Windows 10 has already been used for that Key. Will I probably run into the same problem with a Windows 11 upgrade then?</p>
<p>It’s not free, but almost… You can get Windows 10 (or 11) Professional for $20.00 or less by buying a legitimate Windows 8.1 Pro Product Key (presumably these are OEM licenses) from a reputable dealer and using that key when Windows 10 complains. MS has a lot invested in getting as many people as possible off Windows 7 and 8. It’s a nice clean arrangement and you don’t need to be registered for the Insiders program. The only thing is it’s attached to the system and not portable like full-blown licenses are (or were.)</p>