I am not sure if the use of a Win7 key will activate windows 10 any longer, it should be possible to use the same one as originally used to re-activate a previously activated copy, (but as already stated it should not be needed as the offsite activation should work), The free upgrade for Assistive Technology users has now ended and I am not sure of the status of the unofficial extended free upgrade
The end of the AT offer only came into force on the 16Th Jan 2018, and have not heard anything either way on the general update free offer (that is not recognised by MS), as to changes in status, It will have to be checked by someone with a spare unused W7 key or active Win7/8/8.1 system to upgrade
The initial free upgrade that allowed the use of previous keys to clean install or to upgrade an existing install for free ended on July 29, 2016, but nothing actually changed, so MS could just stop at anytime and not say anything
You can't use Windows 7 product key to upgrade only clean install Windows 10. I'm not talking about free upgrade offered by Microsoft and ended.
With Windows 10 Threshold 2 update, Microsoft has fulfilled the promise to change the Windows 10 activation process and allowed you to use your Windows 7, 8 or 8.1 product keys for activation directly after clean installation.
Activation using GenineTicket.xml definitely still works (I've been trying swapping in and out of Pro Workstation recently). Clean Install Windows 10 Directly without having to Upgrade First Installation Upgrade Tutorials
Don't know about clean install and activating with 7 key. It would only take 10 minutes to check it if you have one though.
I've got a number of old multiuse MAK's that I can use if I want to run a win7 Virtual machine for longer than 120 days for testing or support but not going to waste one of those to check the status of the update process
On other forums, people have tried it and it still works.
Anyway, what is the problem with trying - the 7 key is not invalidated doing an upgrade, so worst case, upgrade does not work.
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