Web services request fails with HTTP status 405; method not allowed

It is possible that the .NET framework is not registered in IIS. This can happen when the .NET framework is installed before IIS. This can be resolved by executing the command %WINDIR%\microsoft.net\Framework\<version>\aspnet_regiis.exe -i, where <version> is the full version of the .NET framework prefixed with a v (i.e., one of v1.0.3705, v1.1.4322, v2.0.50727). On 64-bit versions of Windows, the path is %WINDIR%\microsoft.net\Framework64\<version>\aspnet_regiis.exe -i.