Today me and my collegues tried and run our solution under Windows 8 from Visual Studio. Everything worked as expected but as soon as we called WCF services our system would throw an HTTP 405 message and would stop working.
After a lot of looking around the solution was quite simple. In Windows 8 WCF services are enabled as a feature in IIS. They can be enabled by selection them in:
Control Panel -> Programs -> Programs and Features -> Turn Windows features on or off
Expand .NET Framework 4.5 Advanced Services -> WCF Services, select HTTP Activation.
Even though I’m using .NET 4.0 I went ahead and selected WCF HTTP Activation under .NET Framework 3.5 as well.