Switching Installations to a New Machine

I have Win 10 installed on my current Dell mid-tower - I downloaded the Win 10 installer and retrieved the installer activation "key."

But I just purchased a newer Dell tower with no OS. I want to wipe the drive and install Win 10 fresh, using this same key. I have no use for the older Dell and will probably wipe the drive and give it away.

My question is, how does Microsoft handle the registration on a new machine, using this same activation key?

What should I expect?

Can I "un-activate" the older machine and simply activate the new one?

Thank you!

I have experience primarily with HP PCs, and Dells might be different, but with HP OEM PCs, the product key "locked" to the PC, meaning, it can't be transferred. So, if this is also true with Dell PCs, you can't "migrate" that installation to another PC.

Also, as far as I know, there is no way to "deactivate" an older PC.

If you had a Retail license, you would simply install the OS to the new PC and activate by entering the product key, or if that did not work, you could call Microsoft on a 1-800 number and get the new PC activated. But, MS will not provide any assistance for OEM licenses and will simply tell you to contact Dell.

Link the digital license to a Microsoft account, then transfer the license to the new computer:
https://support.microsoft.com/en-us/help/20530