This article describes how to monitor Windows machines ???private??? services such as CPU load, Disk usage, Memory usage, Services, etc. For this, we required to install an NSClient++ addon on the Windows machine. The addon acts a proxy between the Windows machine and Nagios and monitors actual services by communicating with the check_nt plugin. The check_nt plugin already installed on the Nagios Monitoring Server, if you followed our Nagios installation guide.