Credential Prompt in Outlook/Office 365

An annoying little issue that has popped up a few times when installing Office 365 on a new computer, i am constantly getting Microsoft password prompts asking me to log into 365 for emails etc, if your 365 is integrated into your email and exchange server this is fine, however i am using a on prem Exchange 2016 box so these prompts are nothing more then annoying and frustrating.

I have come across this issue a few times and always have to google the solution which takes 10-15 mins, so as a result i thought i would put up a post to help anybody that comes across this, and also use it as a reference so i have somewhere to find this if it happens again.

To fix this issue all you need to do is open up regedit from the run command.

Then once your in registry you need to navigate to

Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\AutoDiscover

Once your there add a new DWORD and name it “ExcludeExplicitO365Endpoint” and change the value to “1”

Thats it, restart Outlook and your password prompting hell should be no more.