Error: 'an instance of the service is already running' appears when an DMA/SC agent is launch to a m (NETIQKB12315)

symptom
Error: 'an instance of the service is already running' appears when an DMA/SC agent is launch to a machine.

symptom
The process DCTAgentService continues to run on the DMA console machine after the agent task has completed and cannot be killed.

cause
Ultimately, this error is the result of an agent that was launched to a machine and not properly stopped. One of the potential causes of this error is the lack of bandwidth necessary for successful communication using RPC.

fix

Since the agent is installed using RPC, NetIQ recommends 128kps connection speed between the DMA console and agent machines. 

One of the following can be done to stop the agent to continue any agent task:

• Use Service Control Manager or the the services node in Computer Management on the agent machine to stop the Domain Migration Administrator Agent service.
• On the agent machine:
1. Open Task Manager.
2. Go to the Processes tab.
3. Select the process called ADMTAgnt.exe.
4. Click End Process.
5. Click Yes to confirm.
6. Repeat the process for the DCTAgentService process.
• Reboot the agent machine. When a machine is rebooted, the service is automatically removed.
• Using Computer Management or Server Manager connect to the remote machine and stop the Domain Migration Administrator Agent service.
• Use the Service Controller Query Tool (sc.exe) to delete the service from the services applet. It can be obtained from the Microsoft Windows NT4 Resource Kit.

  Example:C:\> sc.exe \\ computername delete OnePointDomainAdminService

Formerly known as NETIQKB12315