I was facing a weird issue where I was putting a valid set of credentials in login prompt of Firefox and was getting login prompt again and again i.e it was not accepting the credntials. I was using Windows Server 2008 R2. I was getting this issue only in Firefox. In IE and Chrome it was working fine.
I am writing the settings which I turned on which was set to off in my Firefox. I opened the following URL in the Firefox "about.config", entered "NTLM" in search box and encountered the following screen:I changed the following options to true:
Below is the screenshot for that:
After doing that Windows Authentication login prompt started accepting my credentials.