When starting up Office products, a screen asking for a code number for multi-factor authentication appears even though I do not remember setting up multi-factor authentication, and you cannot proceed.

Please check the following announcement for the latest information on this problem. Information before it became an FAQ is also available.
How to resolve the problem when authenticating Microsoft Office products on a satellite device

You need to initialize multifactor authentication with administrator privileges.
Please send an e-mail to the address listed under “Other General” in the “Inquiries” section, or contact the Academic Center for Computing and Media Studies.