Understanding the Performance Monitor

The main Performance Monitor method of adding counters lets you start viewing/graphing from that point in time and afterward. However, something may have already happened, that now needs to be investigated. Current counters can be of limited value when something goes wrong.

The Microsoft Performance Monitor allows access to User Defined Reports, which allow you to view past counter values over time. Configured at the time of deployment, these are counters that have been configured to collect data by default. If User Defined Reports have been collecting data, they can be examined after something happens as part of troubleshooting the problem.