I have two computers in my household: one is too old to run PSE 2021, and the other is too new to run PSE 14. I currently have a license only for PSE 14. If I upgrade that license in order to install 2021 on the newer computer, can I keep using 14 on the older one? Or will the PSE 14 license get inactivated for all devices when I buy the upgrade?
The two programs are entirely separate. You can use two copies of each. So, yes, if you use an "upgrade" discount to purchase 2021 for your new machine, Elements 14 will continue to work on your old one. And I'm assuming that you are using Macs. Elements 14 will work on any new Windows computer.