Stop all services. For details, see Monitoring, Starting, or Stopping Services.

Open the Services snap-in.

Check the status of each service, verifying that neither the Channel service nor the Lookup service status is listed as Started.

Note:
The status of the services can also be determined in the Microsoft Lync Server 2010, Group Chat Configuration tool. For details, see Viewing Group Chat Server Status and Configuration Information.

If a service is still running, right-click the server name in the list of services, and then click Stop.

When everything is stopped, restart the server host computer, and start the services. For details, see Monitoring, Starting, or Stopping Services.

Important:
Unless you are having database problems, you should not restart the database server during this process.

Repeat this procedure on all computers running Microsoft Lync Server 2010, Group Chat and Compliance services.

After you restart the system, additional troubleshooting might be required to determine the cause of the problem. Inspect the log files of the failed component, looking for any indications of failures. If the failure is persistent and no troubleshooting options remain, contact Microsoft Customer Service and Support for help, making sure to save all pertinent log files.