installing PSE2020

If you have the disk for the old version you will still have the serial number. Sometimes you need to enter both e.g. old and new serial numbers when making a fresh install of an upgrade. But there should be no problem and there is no time limit on installation.

The downloaded installer is the same for the normal version and the update one. Same program, the only change is the price you pay for having already an older Elements version. You can re-download and use the same license key.

You don't state if you had already installed Elements with the license serial key?

Absolutely no problem if that was not the case, but if the installation has been lost on the computer for technical reasons, it's possible that Adobe does not recognize (and activate) the license for what it may recognize as another computer. So, you'll be asked to re-enter your serial key which will assign the second activation you are allowed to use. You'll be fine but you'll have lost the second activation.

I am curious to know what other expert users can say about that possibility. Once again, no problem if you did not install and activate Elements before the computer has needed being 'worked on'. Otherwise, perhaps contact Customer Care to insure you keep your two activations. That's something they are used to do when a computer has been stolen or destroyed.