问题iis设置4.0后运行程序提示web.config配置错误
解决方法：
管理员身份运行命令提示符分别运行如下命令：
dism /online /enable-feature /featurename:IIS-ISAPIFilter
dism /online /enable-feature /featurename:IIS-ISAPIExtensions
dism /online /enable-feature /featurename:IIS-NetFxExtensibility45
dism /online /enable-feature /featurename:IIS-ASPNET45
