Server Monitor 

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.
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Server Monitor Free Edition 

Server Monitor has powerful features that are very simple to setup. The Free edition monitors web pages, ping response and the Windows event log, and response actions that can send SMTP email notifications, reboot the server, and more.
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