I own Win 7 Ultimate computer, and I have installed Win 10 Pro on a new Ryzen box. My question is, if I try to use the key from Win 7 for activation, will that cause the Win 7 to automatically deactivate? I would not like to deal with the deactivation since it will probably slow down my machine.
If you use your existing Windows 7 key in windows 10 box it will not deactivate your Window 7. In fact you can use any windows 7 or windows 8 keys in windows 10 to get activated freely. In 2015 Microsoft changed the Windows 10 installer disc to also accept Windows 7 or 8.1 keys but it still remain same. This allowed users to perform a clean install Windows 10 and enter a valid Windows 7, 8, or 8.1 key during installation. Windows 10 would then report that key to Microsoft’s servers, and Windows 10’s activation servers would give your PC a “digital entitlement” (now a “digital license”) to continue using Windows 10 for free, just as if you had upgraded.
It won’t affect any factors whatsoever, Microsoft had a free policy upgrade If I recall it was around 2015
As mentioned by other community members, you may need to have a new license key only for a new machine, for same machine upgrade should be working.
Just for Information. Yesterday I upgraded one PC from Windows 7 to Windows 10 version 1903. Desktop had the genuine Windows 7 license and after the upgrade now we got the Windows 10 digital license freely without any issue. So, It seems till date the free upgrade is available.