Need product key

Hello. I have a disc image file (type) [in my downloads folder]: size 682,622 KB; (dated> 11-2-2014); titled OfficeProfessionalPlus_x86_en-us

This makes me think that I purchased Office Professional_Plus; However, after researching my email for this time period -  I do not have the Product Key confirmation message - from where I did obtain this disc image file.

I stated before (on the question forum) - that I did have some medical issues - right at this time. I am some what recovered now. Every one has been very kind - in responses - and, this is appreciated.

My current problem is that my MS-WORD application (that I think is a part of this Office software suite) will not open. I am Windows 10. The Norton Software "Driver Update" software reports this.

I am being requested to "activate" my Office Professional Plus 2013; however, I am not able to "activate" my Office_Professional_Plus.  Instead, the "activation" User Interface just keeps looping me through the account Sign IN process. (so far)

I am looking for suggestions. I am considering "Uninstalling" and RE-installing the Office Professional Plus software - using Control Panel [this was suggested]; However, I will need a "product key" (25 characters) - I think - to re-install (if the Disc Image File is the program install software pack).  So, the question is: WHERE do I find this Product Key? We moved, related to my medical issues - to be closer to Ohio State University. Does Microsoft keep a record of purchases? - and the Product keys? The date (of interest) appears to be November of 2014. My husband's accountant can (maybe) produce the product purchase Bank record. However, I do not want to trouble them (to look) - if I do not have to.

Thank you - again.  Susan