How to use a key to upgrade to windows 10?

[cstiles96]

So I am on a pc running windows 8.1 PRO. What I want to do is use a key from a different computer that is no longer in use and use it to upgrade to windows 10. Can I still keep my windows 8 key and use it on another system? or do I have to install the other operating system first then upgrade? The reason I want to do this is so I can have my windows 8 copy saved and not lock to my motherboard and turn into windows 10 and be locked to my motherboard. Any help will be appreciated. Thanks!

 

[unksol]

If you have Windows 8.1 OEM it is already locked to your motherboard. Happened as soon as you upgraded from 8. If it is a retail copy the Windows 10 upgrade is also retail.

You can not use the OS from another system unless it is a retail copy.

 

[ex_bubblehead]

As soon as you upgrade to Windows 10 the original license is consumed and no longer usable. You cannot upgrade and continue to use the original license. No Windows upgrade has allowed this.