Recently one of our client faced with a problem when he tried to open up the WCF after deploying, he checked and realised that he has the WCF features turn on and also .NET framework turn on but he is still getting a 404.3 error. What happened may be because the WCF services is not registered.
Open up command prompt in admin mode and run this after changing directory to the Windows Communication Foundation folder
cd C:\Windows\Microsoft.Net\Framework\v3.0\Windows Communication Foundation\ ServiceModelReg -i
This fixed the problem. 🙂