Retrieving the COM class factory for component with CLSID {00024500-0000-0000-C000-000000000046} failed due to the following error: 80070005.

Please refer the following solution:

http://blog.crowe.co.nz/archive/2006/03/02/589.aspx

Note: If still it doesn't work You have to Impersonate a specific user in code.

This solved one of my problem where I was creating a Excel on runtime and saving it to server.

The problem is that by default Microsoft Excel as a COM object can only activated by the following accounts:

• Administrator
• System
• Interactive

So you can impersonate section of code which needs the above privilege of a user and then you can undo the impersonate when you are done with it.

Here is the solution:

http://support.microsoft.com/kb/306158