If Reliability Monitor stops updating, open Event Viewer (see tip 26), expand Windows Logs, right-click System and choose Clear Log > Clear.

Launch Task Scheduler from the Start menu's Search box, select View > Show Hidden Tasks, then expand Task Scheduler Library > Microsoft > Windows > RAC.

With RAC selected, right-click RACAgent in the middle pane and select Run. Its status should then change to Running, indicating that the Reliability Monitor is working correctly once again.