To use Integrated Windows Authentication (SPNEGO authentication) on Mozilla Firefox for Windows, the following settings are required:

1. Start Firefox, enter “about:config” in the address bar, and then press the Enter key.
   

2. Click “I accept the risk.”
   

3. Enter “network.negotiate-auth.trusted-uris” in the search form and then double-click “network.negotiate-auth.trusted-uris,” which appears below it.
   

4. Enter the URL of the Integrated Windows Authentication provider and then click “OK.”
   

5. Enter “network.negotiate-auth.delegation-uris” in the search form and then double-click “network.negotiate-auth.delegation-uris,” which appears below it.
   

6. Enter the URL of the Integrated Windows Authentication provider and then click “OK.”

   [ Reference ]

   Contact your administrator for more information about the URL of the Integrated Windows Authentication provider.

   

7. Restart Firefox.