Windows 10: How can I deactivate or reset my Office 2016 product key across all devices?

I didn't use a credit card when I bought the license online. I can't seem to use my product key to activate Office. I tried calling MS Office support, but I received a terrible response as my call was simply forwarded from one person to another.

:)

 

Office 365 or Office 2016

Under info for the new office listing on My Visual Studio it states.

Office Professional Plus 2016 (x86 and x64) - (Multiple Languages)
To obtain the product, follow these steps:

Step 1: Get your product key by clicking the ‘Get key’ button on the right.

Step 2: Go to the Office website by clicking the ‘Get it now’ button.

Step 3: Enter your 25-character product key and continue as directed on the site.

Released: 9/23/2015

And for the discontinued it states.

Office Professional Plus 2016 (Discontinued)
Info
Keys
Office Professional Plus 2016 (x86 and x64) - DVD (English)
No additional details are available for this file.

Released: 9/22/2015
SHA1: 213A8A0F8849516704101CB6C49F6A027B0D6D5F
File name: en_office_professional_plus_2016_x86_x64_dvd_6962141.iso

I'm thinking option one is going to be my only option. I'm fine with that as long as I can get Outlook to work with my ISP's pop3 e-mail. Last time I tried that with the new 2016 install I could not get it to work, no way no how. All the same settings that work with the ISO install?

EDIT: I should mention, for me as far as I know, neither of these options are a subscription. They use two different keys but they are perpetual one time activation licenses. I only ran the new download briefly though, as I could not get outlook to work. I bailed and went back to what works.

 

Lost Product Key to Microsoft Office ....

The newer versions of Office (365/2016/2013) don't require product keys for second time installation. When you install this first time and activate, the product key gets stored in digital format on Microsoft activation servers. For any subsequent downloads
and activation, you need to login here and install and activate.

No need of any product key only for 265/2016/2013. For versions below 2013, you will require product keys.

You will have to first deactivate Office license which was installed on old computer otherwise it will be counted as a license. Hence, if you were allowed installation on one computer, you will not be able to activate on new computer. If your license was for
say 5 computer as in case of Office 365 Home, now your validity will be for 4 computers.

Hence, deactivate first and then install and activate.

1. Deactivate your existing installation -
https://support.office.com/en-us/article/Deacti...

2. Install Office again on a new computer -
https://support.office.com/en-us/article/Downlo...

 

Unable to recover office 2016 key

You don't require a product key for MS Office if you have installed and activated it. You require it just once, for the first time installation and activation.

You also don't require product DVD again as this is available online now.

Once you install MS Office 365 / 2016 and activate it, a digital signature corresponding to your computer gets stored in Microsoft servers.

Now whenever you login to your Microsoft account, it will check whether you are trying to install on the same computer or not. It won't ask for the product key again.

Hence, go ahead and reinstall. Follow the Help below to reinstall -

https://support.office.com/en-us/article/Downlo...

In case, you want to install on a different computer, you will have to first deactivate Office license which was installed on old computer otherwise it will be counted as a license.

Hence, deactivate first and then install and activate.

Deactivate your existing installation -
https://support.office.com/en-us/article/Deacti...