Hi All, Whenever I am trying to read linked contacts, recipients ands user properties from Outlook appointment items, i am getting below exceptions: 1)while reading linked contacts Unable to cast COM object of type 'System.__ComObject' to interface type 'Microsoft.Office.Interop.Outlook.Links'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{0006308A-0000-0000-C000-000000000046}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)). at Microsoft.Office.Interop.Outlook.Links.get_Count() 2)while reading user properties Unable to cast COM object of type 'System.__ComObject' to interface type 'Microsoft.Office.Interop.Outlook.UserProperties'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{0006303D-0000-0000-C000-000000000046}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)). 3)while reading recipients Unable to cast COM object of type 'System.__ComObject' to interface type 'Microsoft.Office.Interop.Outlook.Recipients'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{0006303B-0000-0000-C000-000000000046}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)). at Microsoft.Office.Interop.Outlook.Recipients.get_Count() Any idea why this is happening only on my machine and working fine on all the other test machines. I have Outlook 2003 and I have installed all the office updates. Please Help....