服务器上部署DNN失败

几乎折腾了一天也没有能在网通线路的那台服务器上安装好DNN4，怀疑了很多地方，最终还是那个该死的：

Server Application Unavailable

The web application you are attempting to access on this web server is currently unavailable.  Please hit the "Refresh" button in your web browser to retry your request.

Administrator Note: An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur.

怀疑是服务器的问题，等到晚上回到家远程连接到电信线路的服务器上，竟然是一样的结果！

一直以为IIS的错误信息就在网站log里，看了半天也看不出个什么来。后来忽然醒悟：“Can  be found in the application event log of the web server",于是打开了windows的事件查看器，在程序日志里，发现了这样的提示：

事件类型: 警告
事件来源: ASP.NET 2.0.50727.0
事件种类: 无
事件 ID: 1073
日期:  2007-2-10
事件:  10:05:25
用户:  N/A
计算机: CNTQ-1
描述:
Failed to initialize the AppDomain:/LM/W3SVC/214077270/Root

Exception: System.IO.FileLoadException
Message: Could not load file or assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. 拒绝访问。
StackTrace:    at System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)
   at System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection)
   at System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection)
   at System.Activator.CreateInstance(String assemblyName, String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, Evidence securityInfo, StackCrawlMark& stackMark)
   at System.Activator.CreateInstance(String assemblyName, String typeName)
   at System.AppDomain.CreateInstance(String assemblyName, String typeName)
   at System.AppDomain.CreateInstance(String assemblyName, String typeName)
   at System.Web.Hosting.ApplicationManager.CreateAppDomainWithHostingEnvironment(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters)
   at System.Web.Hosting.ApplicationManager.CreateAppDomainWithHostingEnvironmentAndReportErrors(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters)

有关更多信息，请参阅在 http://go.microsoft.com/fwlink/events.asp 的帮助和支持中心。

事件类型: 错误
事件来源: ASP.NET 2.0.50727.0
事件种类: 无
事件 ID: 1088
日期:  2007-2-10
事件:  10:05:25
用户:  N/A
计算机: CNTQ-1
描述:
Failed to execute request because the App-Domain could not be created. Error: 0x80070005 拒绝访问。 

有关更多信息，请参阅在 http://go.microsoft.com/fwlink/events.asp 的帮助和支持中心。