You would need to wipe it off - i.e. perform a "clean install" of Windows.
Your old Windows installation will have the wrong chipset drivers on there from your old PC. It would be like building your new house on quicksand - only a matter of time before you have big problems.
When booting off your Windows 10 USB media (which you can create free here
direct from MS), select a Custom Install and delete all partitions on the drive. Note this will get rid of what's on the drive so back up any important files or games you don't want to redownload first.
You can often copy over game files without needing to redownload, at least.
It's possible on every major digital storefront... except the Microsoft Store.
PCG's article might need a tiny bit of an update for one or two of the clients, but it gives you the gist.