Photoshop elements 12 reinstall chat not helpful

ADB-2870069-V8S1 is the chat reference. I tried to reinstall Photoshop but got "Serial Number Invalid".  I assumed that the  serial number was canceled because the program can only be downloaded to two computers. I had first loaded to computer #1. The computer died. I bought a new computer (#2) and successfully downloaded. Computer #1 was repaired but all programs were erased. I tried to download again to computer #1 (the third download) and got the "Serial Number Invalid" message. I assumed that after the second download the serial number was cancelled to prevent a third download.

     The chat expert said that the serial number was still good. He would not reply whether or not he had made any changes. How can I get the serial number to be accepted?