I'm posting this here to save someone the headache that I had to go through.

After installing Office 365 as a test, and then removing it - the excel options were going from QB.

I uninstalled, reinstalled, repaired, etc. etc. with no luck.

using regedit - Delete the 1.9 key under:

HKEY_CLASSES_ROOT\TypeLib\{00020813-0000-0000-C000-000000000046}

Then restart QB - problem solved.