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Administrator Note: An error message detailing the cause of this specific request failure can be found in the system event log of the web server. Please review this log entry to discover what caused this error to occur.
Error in Event Viewer: aspnet_wp.exe could not be started. The error code for the failure is 80004005. This error can be caused when the worker process account has insufficient rights to read the .NET Framework files. Please ensure that the .NET Framework is correctly installed and that the ACLs on the installation directory allow access to the configured account.
aspnet_wp.exe could not be launched because the username and/or password supplied in the processModel section of the config file are invalid.
Solution: Check out this microsoft support article >> http://support.microsoft.com/default.aspx?scid=kb;en-us;811320
For me, particularly after running this command line script it started working.
cacls C:\WINDOWS\assembly /e /t /p domain\ASPNET:R