Hi Greenbergman,
Thank you for the posting in our forum community.
Based on your description, generally if the password have changed for email account from online, then password window will
automatically popup at the time of open Outlook for Microsoft Exchange account. Because, this password related thing is comes from the server side.
Further, we would like to suggest you that kindly clear your credential from window credential manager with associated
Outlook accounts, after that try to identify the issue. Go to Control Panel > Select
User Accounts > select Credential Manager > click on
Windows credentials > Remove your Hotmail related credentials from windows credentials.

Since, you are using Hotmail account and we are focusing Office 365 for Business related issue. So for further better guidance,
we will help you to move your thread in proper category for proper handling. We are truly appreciating your cooperation in our forum community.
Regards,
Darpan