IIS error while trying to start WebMatrix

When I try to start WebMatrix, I get a warning that "IIS Express cannot be initialized. Make sure it is installed and configured correctly."

I uninstalled and reinstalled IIS Express and WebMatrix with no change in this behavior. The advice I could find on the network was to take responsibility for the HKEY_CLASSES_ROOT \ Microsoft.IIS.VersionManager registry key and replace all the permissions of the child objects with the permissions of this registry key. It did not help.

In the event viewer, I see .net runtime exceptions every time iisexpresstray.exe or webmatrix.exe is run:

• System

  • Provider [Name] .NET Runtime
  • EventID 1026 [Qualifiers] 0 Level 2 Task 0 Keywords 0x80000000000000
  • TimeCreated [SystemTime] 2012-09-29T21: 28: 02.000000000Z EventRecordID 162768 Channel Usage Security

• EventData Application: iisexpresstray.exe Framework Version: v4.0.30319 Description: The process was aborted due to an unhandled exception. Exception Information: System.ArgumentNullException> Stack: in System.Runtime.InteropServices.Marshal.FinalReleaseComObject (System.Object) in Microsoft.Web.VersionManager.IisExpressVersion.Dispose (Boolean) in Microsoft.Web.VersionManager.IisVers

I would really appreciate any help in diagnosing and fixing this problem. WebMatrix will be an almost integral part of the project that I will come soon. Thank!