From Power Admin:
PA Server Monitor is a Windows service that monitors the health and availability of Windows servers, network services (on Windows, Linux and other operating systems), and devices. No agents are needed to monitor remote servers. Also includes rich reporting on most monitored resources.
PA Server Monitor can watch: CPU, memory, disk space, Event logs on local and remote Windows servers, Ping response times, Changed files and directories (great intrusion detection), Windows services, Web page load time and content, Custom script results, Local and remote directory quota monitoring, Network Interface Card (NIC) usage, Performance counter values with threshold warnings, POP, IMAP and SMTP mail server availability status, Server temperature and more.
Remote/distributed monitoring of servers across the Internet, without a VPN, is supported with our Satellite monitoring engine.
PA Server Monitor is easy to install on your Windows servers. It can monitor Windows servers, network devices, web sites, and any network drive that Windows can access.
PA Server Monitor installs fast and can self-configure even faster. Download the free trial of the Ultra, Pro, or Lite version. You can literally be installed and monitoring in under 2 minutes.