I was wondering if the DPAPI will still work properly if a user doesn't have a a login password (like most of the home users). I can't find this information on Google or in the official documentation and I can't test it because the computers at work can't be without a password.
Yes, but it's not quite as secure. DPAPI encrypts data with a master key, which is independent of the user password. When the user has a password, the master key is encrypted with the user's password. Without a password, an attacker with local access (via another user account) might extract the master key. However, once an attacker has local access to the system it's game over anyway. DPAPI is just a damage limitation system, really.