401 - Unauthorized in IE7 only with windows authentication.

Question

I've created an intranet site that uses windows authentication

In chrome I can access the site instantly, and in FF it requires Active Directory login. But with IE7 I'm getting the following error:

401 - Unauthorized: Access is denied due to invalid credentials. You do not have permission to view this directory or page using the credentials that you supplied.

Im unsure as to why its okay in other browsers but not IE? Any help appreciated.

Thanks

Answer 1

Solution:

IE is using Kerberos and not falling back on NTLM like Chrome and Firefox. You must force NTLM authentication in IIS7.5 by following these steps:

1. Select your site.
2. Double click authentication.
3. Select "Windows Authentication" (ensuring that it is enabled).
4. Click "Providers..." in the right hand column.
5. Select NTLM and click "Move Up".

Link: windows authentication not working in ie7