Solved Just to be sure, I upgraded and restored my backup I can upgrade free

[Max Pen]

I upgraded to windows 10 and went back to windows 7 so now I can upgrade to windows 10 at any time for free right?

 

[Brink]

Hello Matt,

If the Windows 7 was activated when you upgrade to Windows 10, then yes. A digital entitlement would have been created on Microsoft's activation server for that specific PC to activate Windows 10 with in the future.

Activate Windows 10 - Windows 10 Forums