Activation Key

If you are looking to download the installation file, there is no download for PSE 7 available from Adobe.

I've misplaced my activation key for Photoshop Elements 7

By @Elaine250492409vzj

The redemption code is used only once to get the serial number:

https://helpx.adobe.com/download-install/kb/redemption-code-help.html

 I do have the serial number. 

By @Elaine250492409vzj

Then you don't need the redemption code.

To expand on what Greg_S. said:

Please go to Adobe Customer Service and only ask to have your activations reset (make sure to sign in to your Adobe account first and allow popups on your browser):
https://helpx.adobe.com/contact.html?rghtup=autoOpen will automatically open the chat window.
Type "Agent" in the chat box to bypass the chatbot and be connected to a person.

You may also be able to contact Adobe by phone:
https://helpx.adobe.com/contact/phone.html

If you have exceeded the maximum activations for your license, you need to contact Adobe Support and tell them to deactivate the license.