Not sure how to point you, but you own that license and should be able to use it on any PC.
Easiest path is if they were still providing software on discs and you can find it!
If you are like me, I have no reason to update Office or any other program until I'm forced.
If you don't have a disc, do check your Microsoft Account and see if it got registered. I think it's unlikely you have Windows without having a Microsoft Account.
https://account.microsoft.com/account
I switched to 365 so I'm guessing, but open any office app (like Excel), click on "File" and see if there is an "Account" option. This will give you details on the license and maybe a link to your Microsoft Account??