Error when using Excel Object_ASP.NET_Access denied.

Hi Folks,

In asp.net using VB I am using an excel object as ....

Dim xlApp As New Excel.Application. (after com referencing)
....

Its working fine in the development server but it is giving error when I install in the production server.

The error says ....

Access is denied.

Exception Details: System.UnauthorizedAccessException: Access is denied.

I have given write permission to the IUSR_machineName of the virtual directory.

I have given write permission in the virtual directory of the IIS Server.

I am using <identity impersonate="true"/>

I tried giving username and password; every thing failed.

Please help!!! Thanks in Advance.