Automatic Logon in Intranet Zone

Internet Explorer has this feature where it automatically tries to logon to websites requiring authentication, using local windows credentials, when the website is within the Intranet zone. This occasionally fails and going to the website prompts for a username password, even though it is the same as the windows logon password.

This is the case for Windows Sharepoint Services websites setup within the local intranet that use the local Active Directory for authentication. This authentication can happen seamlessly if using a computer that is authenticated with a valid user from the same Active Directory.

When IE's automatic logon feature fails sometimes, the password for that website needs to be reset / removed. This can be done by opening the 'Stored User Name and Passwords' dialog using the Run command "control keymgr.dll" and deleting the record corresponding to the website. If necessary, add the website to the 'Trusted Sites' and change the security settings for that zone to 'Automatically logon with current username and password'. Obviously if there are other websites in the same zone, this is a security risk. Further troubleshooting may be necessary to fix the problem without adding the local website to 'Trusted Sites'.