Someone has told me that after clicking on the Transination Navigation Key
option, everytime Excel is restarted it goes back to the option, no matter
what he does.

He even tried reinstalling Excel, but the option remains "ticked" and can
only be "unticked" during the current session of Excel. As soon as he closes
Excel and opens it again, the option appears ticked.

Anyone with an idea of how to sort this out?