SP1 changes the default COM ( Component Object Model) permissions in Windows Server 2003. Among these are that only administrators have Remote Activation permission, and the Launch permissions, so that user attempts at remote calls will fail.
NOTE: Some 3rd-party backup applications may fail if not run under a domain administrator context.
To determine if you are experiencing a permissions issue, you must first turn on DCOM error logging.
If you determine that your problem is a permissions issue:
1. Open Component Services from the Administrative Tools folder of the server's Start menu.
2. Expand the Component Services \ Computers container.
3. Right-click My Computer and press Properties.
4. Select the COM Security tab.
5. Press Edit Limit in the Access Permissions or Launch and Activation Permissions area, depending on where the issue occurs.
6. Select or Add the account that is specified in the event log error, and check Allow for Remote Access permissions.
7. Press OK and OK.
NOTE: Do NOT forget to turn off DCOM error logging.