The Sitecore installer automatically installs Sitecore counters
Counters can be installed separately when performing manual installations
Counter Configuration Settings
Counters.Enabled indicates if performance counters are enabled. Setting this to “false” stops the application from updating Sitecore performance counters.
Counters.InstanceName indicates the counter instance name that will be used when updating and reading Sitecore-specific counters. This setting must be changed if you plan to monitor Sitecore-specific counters while running multiple Sitecore web applications on a single server.
Counters.ResetOnStartup indicates if performance counters instances will reset their values to 0 on application restarts.