trying to deploy a vb.net dll to clients; on some machines the following
run-time error occurs:

Unable to case COM object of type 'Microsoft.Interop.Excel.ApplicationClass
to interface type 'Mirosoft.ofiice.interop.Excel._Application'. This
operation failed because the Queryinterfacecall on COM component for the
interface with IID '{000208D5-0000-0000-C000-0000000047}' failed due to the
following error: Interface not registered (Exception from HRESULT:
0x80040155).

On some machines, this run-time error does _not_ occur.

Reading on the net I found some comments about the PIA not being installed,
but I don't know about it enough.

One of the machines this run-time occurs for is with completely new
installtion of office excel 2003 (standard edition).


The reference in the dll is to the COM interop of office 11 (GAC).


Has anyone got an idea how to solve? this has to work on client machines
without messing registry or requireng additional installations, so I hope for
a fix in the dll reference/code.

Thanks in advance.