Performance Monitor is a Windows NT 4.0 Administrative Tool for monitoring the performance of Windows NT workstations and servers. It uses a series of counters to track data, such as the number of processes waiting for disk time, the number of network packets transmitted per second, and the percentage of processor utilization. You can watch this data in real time, log it for future study, use it in charts and reports, and set alerts to warn you when a threshold value is exceeded.