今天发现.NET 3.0 WCF HTTP Activation没有装，就顺手装了一下，结果以前的WCF都跑不起来了
Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.
这个好诡异，以前都正常的，这个DLL也肯定是有的
http://support.microsoft.com/kb/2015129
如果先安装了.NET Framework 4.0，之后安装低版本的.NET Framework或者.NET 3.0 WCF HTTP Activation，都会出现这个问题，解决的方法也很简单
To resolve this issue, run the following command line:
aspnet_regiis.exe /iru
The Aspnet_regiis.exe file can be found in one of the following locations:
%windir%\Microsoft.NET\Framework\v4.0.30319
%windir%\Microsoft.NET\Framework64\v4.0.30319 (on a 64-bit computer)