in addition to dj_paige's hint, you should have a look there too, to see what's stored/saved about your accounts at Adobe's database:
https://www.adobe.com/account.html >>> see My productsView all >>> These registered products are associated with your Adobe ID. >>> Name >>> Serial number.
If not successful use - as said above - http://helpx.adobe.com/x-productkb/global/find-serial-number.html >>> I lost my serial number >> see comment
The last time Adobe suggests so too this https://helpx.adobe.com/contact.html?step=ZNA_downloading-installing-setting-up_licensing- activation
If necessary and for further questions click through http://helpx.adobe.com/contact.html and if "open" please use the chat, I had the best experiences. I quote from Adobe's employee Preran: The chat button is activated as soon as there is an agent available to help.
Thanks!!! It worked and I'm so happy to have it back.