Why is windows asking for another product key

[Windows Central Question]

I'm trying to move from windows 10 Enterprise to Pro, I downloaded the ISO file and tried the installation, it asks me for a product key, though windows is already activated. I tried inputting my current product key, but it says product key not for this version of windows. Please what do i do?

 

[realwarder]

Enterprise Windows has a different license mechanism than Pro. So you cannot use the same license in both.

Stick with Enterprise?