ASP.NET 3.5 - Server Application Unavailable

Jeg har lidt problemer med at få .NET framework 3.5 til at køre på en server med Windows 2003 Server.

IE viser følgende fejl, når jeg forsøger at tilgå en ASP.net 3.5 applikation:

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.
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Log filen viser 2 events:

Failed to initialize the AppDomain:/LM/W3SVC/25040/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. Access is denied.

StackTrace:    at System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)
  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)

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

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Failed to execute request because the App-Domain could not be created. Error: 0x80070005 Access is denied. 

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

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Er der nogen, der kan hjælpe med dette problem?