Before adjusting DCOM settings, you may want to turn on DCOM debugging to get specific information on the exact DCOM error that is occurring. You can enable error logging by changing the registry and then restarting the DCOM process (the Exele OPC Client) that you want to examine. The DCOM process that you want to examine determines whether you have to restart the computer.
1. Click Start, click Run, type regedit, and then click OK.
2. Locate the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole registry subkey.
3. Right-click the Ole value, point to New, and then click DWORD Value.
4. Type ActivationFailureLoggingLevel, and then press ENTER. Double-click ActivationFailureLoggingLevel, type 1 in the Value data box, and then click OK.
5. Right-click the Ole value, point to New, and then click DWORD Value.
6. Type CallFailureLoggingLevel, and then press ENTER. Double-click CallFailureLoggingLevel, type 1 in the Value data box, and then click OK.
7. Restart the DCOM program, and then examine the System log and the Application log for DCOM errors (Event Viewer). The error messages in the Windows event log contain information that you can use to help resolve the permissions issue.
You can turn off DCOM error logging by changing the ActivationFailureLoggingLevel value and the CallFailureLoggingLevel value to zero.