Windows Authentication Credential box asking multiple times in IE8 and IIS7

Question

We have couples of intranet websites hosted on the Windows 2008 Server and all of them are using the Windows Authentication mode. For Example,

1. SiteA
2. SiteB
3. SiteC
4. SiteD (Not working)
5. SiteE (Not working)

Among them, without any special modification, SiteA, B and C are working while Site D and E are not working in IE8. I double checked the settings and I am sure that I set all the same setting. But when I use Firefox to test, all sites are working.

In IE8, for SiteA, B and C, I don't even need to type my credential and it logs in automatically by using my AD account. But for Site D and E, it asks the username and password for 3 times and after that, I got the following error message even though I provided the correct one.

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.

I attached my Authentication and Authroization setting for those sites which have errors.

The advanced settings is as follow:

How can I configure these erroneous sites to work like SiteA, B and C? What did I miss?

We don't have Security Tab in IE8 coz of the company policy and we don't tweak anything for SiteA, B and C to work correctly.

Thanks everyone.

Answer 1

This procedure fixed it for me...

1. Open IIS Manager
2. Browse to and click the site in question
3. Double click the Authentication icon
4. Right click on "Windows Authentication" and click "Providers"
5. Move "NTLM" to the top of the list.

Answer 2

Thats correct, NTLM has to be at the top of the providers. I also wanted to note that, Extended Protection in the Advanced Settings has to be turned OFF as you have done up there. This also fixes the authentication problems that happen if you connect from chrome or firefox.