Error occured during the debugging the page?

when i run my application it is the error i get...

This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem. (Exception from HRESULT: 0x800736B1) Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Runtime.InteropServices.COMException: This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem. (Exception from HRESULT: 0x800736B1)

Normally if you want to use interop with ASP.NET, you need to impersonate your web site as someone who actually has the right to run the application you want to interop (eg: Word, Excel..).

<identity impersonate="true"
      userName="domain\user" 
      password="password" />