I originally had Windows 8.1 Pro installed on a machine. This was upgraded to Windows 10 Pro a while ago.

Unfortunately last night my OS SSD died and I've just installed a new one and installed Windows 10.

According to this [Microsoft Article](https://answers.microsoft.com/en-us/windows/forum/windows_10-win_upgrade/reinstalling-windows-10-after-upgrade/578d0b7f-57e4-4893-b9d1-6cfac0d6290a?auth=1) I need no Product Key as Windows will automatically activate online.

I have linked the new Windows 10 installation to the same Microsoft account but I'm still unable to get Windows to activate.

I had written down the product key as shown to me by the previous Windows 10 installation but that starts with two 0s which you can't even type into the product key box as it reports as an invalid character.

Has anyone else gone through this process and successfully activated Windows 10?

I'm worried if the change in hardware is the issue ... surely this is a very common scenario for the need to reinstall Windows?