Can I still retrieve my retail windows 8 key after upgrading to windows 10?

[KILLAFROSTBYTE]

I upgraded 3 custom desktops, all with retail key copies of windows 8, to windows 10 a couple months and I was wondering if it was possible to retrieve the old windows 8 keys since I dont have the email the keys came in anymore? I heard that if I got windows 10 by upgrading, it would be tied to the hardware and if I make any changes to it I would have to rebuy a copy of windows 10. There's a lot of conflicting info when I googled my problem which is why I'm asking here.

Also, on the topic, if I were to buy a copy of windows 10 from a key selling websites, like here:

http://cheapdigitaldownload.com/windows-10-professional-digital-download-price-comparison/

would this be considered a "Retail" version of windows 10 that comes with an activation key? I would purchase a key if it meant I could reuse it after upgrading or getting a new PC, but I'm not sure the retail version's key is a one-time use that's also tied to the hardware it was installed on, or if it can be reused as long as its on one PC at a time?

Thanks in advance!

 

[USAFRet]

1. That website you link is NOT a valid source. At all.

2. Your original Win 8.1 license. Given that it was a Retail license, your Win 10 should allow movement to different hardware. Key word being should. If it does not, a call to MS should fix that.
But no, you cannot retrieve the old 8.1 license key from a Win 10 system.

 

[Hlsgsz]

1. That website you link is NOT a valid source. At all.

2. Your original Win 8.1 license. Given that it was a Retail license, your Win 10 should allow movement to different hardware. Key word being should. If it does not, a call to MS should fix that.
But no, you cannot retrieve the old 8.1 license key from a Win 10 system.

Does the key itself get changed when updating to 10?

 

[USAFRet]

1. That website you link is NOT a valid source. At all.

2. Your original Win 8.1 license. Given that it was a Retail license, your Win 10 should allow movement to different hardware. Key word being should. If it does not, a call to MS should fix that.
But no, you cannot retrieve the old 8.1 license key from a Win 10 system.

Does the key itself get changed when updating to 10?

Yes. There is a generic license key that is created when you Upgrade to 10.
But the 'license key' is a whole different concept with with Upgraded Win 10.
It is a hash of your original key, and some info from your hardware. This is stored at the mothership.