To change the Exchange login requirements from Domain\user name to user name, you need to change the authentication settings for the OWA (Outlook Web App) website. This change will also effect the ECP page for the Exchange Admin Center.
Login to the Exchange Admin Center
Once logged in
- Click on Servers from the left pane
- Select Virtual Directory from the top selection tabs
- Double Click on OWA(Default Web Site) or Select it and click on the edit button
The Virtual Directory options window will popup.
- Click on Authentication
As shown, this will be set to Use forms-based authentication and te format is Domain\User name
- Select User name only and browse for the domain name.
- Click Save
A warning will come up informing you that IIS needs to be restarted.
- Log off from the Exchange Admin Center
To restart the IIS:
- Log on to the IIS server hosting the OWA, in my case the exchange server
- Open a command prompt window with elevated rights (As Administrator)
- type the following command as shown:
Now try to login the Exchange Admin Center, with the username and password only.
Hope you find this useful.