Firefox asks user name and password while accessing localhost

This problem is been around for a while and there are very few references available in online regarding this issue.

This is mainly IIS problem with Windows Authentication. To solve this, please follow the below steps:

Start -> Control Panel -> Administrative Tools -> Internet Information Services
Expand your Computer -> Web Sites -> Default Web Site
Right click Default Web Site and choose Properties
Click on the Directory Security tab
Click on the Edit button under “Anonymous access and authentication control” group
Check the “Anonymous access” and verify that the user name is IUSR_<your-computer-name> and check the “Allow IIS to control password” checkbox.
Check the “Integrated Windows authentication” checkbox
Click OK and OK again and close the Internet Information Services window
Open Firefox
Type about:config in the Address bar
Type network.automatic-ntlm-auth.trusted-uris in the filter box
Double click the resultant row and type localhost and press OK
Now, close Firefox and reopen Firefox
If you visit http://localhost now, there will not be any problems.