Find Ms Office Prod Key From Backed Up Data Files?

I wiped my boss's computer and reinstalled Windows 10 planning to use my own Office installation media to reinstall it, but I forgot to identify the product key before wiping the drive.

I have the entire previous contents of the hard disk backed up, except for the Windows directory. So I have the whole Users folder, Program Files (x86 and 64), Program Data folder, etc.

Will any of these be of any use in identifying what the product key was? I don't want to admit this oversight to him so I don't want to have to ask if he knows where his install disc is.

Edit: I did a lot of poking around before posting this but then found this after posting.. don't know if it will help.


""From what I’ve read, MS uses a file called TOKENS.DAT to store encrypted product activation keys:

C:\ProgramData\Microsoft\OfficeSoftwareProtectionPlatform\Tokens.DAT

C:\Windows\ServiceProfiles\NetworkService\AppData\Roaming\Microsoft\SoftwareLicensing\Tokens.data
""

Unfortunately looking at the copy of this file on my own machine, it's 6 megs and full of code. Not sure how to find the key, if it's even readable.