and download and install Magic Jelly Bean. Once you run it, it will show you your registration keys for Windows, office and a few other items. I don't suggest considering it for more than that. I sense the ownership of the product has changed, as this later version is kinda different than in the past - aggressive sales etc.
It should also tell you which version of Office is installed.
But no, there is no one or a few files that might be part of an existing Office install, and can return the entire program if used. This can be a stickler.
Look through the info here
about moving everything to a new user account. It may look like a good bit, but in truth it is only making a new account, rebooting to it once, then rebooting to Safe Mode, Admin account, and copying some files. This may very well correct much of the issues occurring there now. And you can test it, without changing anything on the current account.