Update from 10 to 10 pro failed got new retail key from support for fr

So I just bought new msi ge62 laptop and it had windows 10 home, I tried to transfer my old 8 pro key and make it 10 pro but it kept saying that "this windows version cannot be updated".
So I called local Microsoft support number and they couldn't make it work either, so that support guy made me new 10 pro retail key for free!

My question is that is my old 8 pro retail key still valid and can I keep my current 10 pro install in my old laptop too?

They are separate keys but still I wonder if he somehow disabled that older key or is it still valid?

Did I really "score" full retail 10 key with my cheap 15€ 8 pro key without even losing that 8 pro key in the process?

Your Windows 8 Pro key is not disabled. Normally what you have to do to upgrade Windows 10 Home to Pro with a Windows 8 Pro product key is first upgrade to Pro with the generic Windows 10 Pro product key, then use your Windows 8 Pro product key to activate it. Sounds like you got lucky and a good deal. Make sure to write down the 10 Pro key and keep it safe.

NavyLCDR said:

Your Windows 8 Pro key is not disabled. Normally what you have to do to upgrade Windows 10 Home to Pro with a Windows 8 Pro product key is first upgrade to Pro with the generic Windows 10 Pro product key, then use your Windows 8 Pro product key to activate it. Sounds like you got lucky and a good deal. Make sure to write down the 10 Pro key and keep it safe.

Ok it is in a txt file in my external drive and in my gmail box.
But that generig key with non activated windows 10 pro was the first thing that I tried to get.
when I input that key it started the operation and rebooted, however after it rebooted it said something like "this windows version cannot be upgraded"
I cannot be sure of exact wording because my os is in Finnish so that is just my translation of the message.

But I got that error with generic key and with my 8 pro key and even with that new 10 pro retail key, so after that I said fu*k it and reinstalled windows 10 pro with generic key inside a pid file.

So that's why they give me 10 pro key.

So now I have 2 working 8 pro retail keys (bought from Microsoft when they where 15€ peace and also 10 pro retail key?!

Whoever said that legal windows pro keys are too pricy where wrong (rolleyes)

Thanks for the info and happy new year, now is that time again where we need to learn how write 2016 in all forms and documents instead of 2015.

You can run all the product keys through Superfly's Showkeyplus program using the check product key menu option. It will tell you what versions of Windows they are for. Maybe it is possible the product keys are for N or Single Language editions:
Showkey - Windows 10 Forums

nope is says that my bios key is win 10 RTM Core OEMM so it shouldn't be that windows 10 n series either, even tough i live in eu area (Finland) i haven't never seen any of those n series windows versions.
currently i have that free windows 10 pro retail installed and this also shows it to be the case, so my old pc sought be fine with it's old 8 pro key (upgraded to 10 pro) and it will not start to cry about that my new pc has once been activated with that key.

now this new pc has that new 10 pro retail key and that old pc has it's old key.