PA 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 includes several response actions such as email, reboot, etc. Monitored resource reports too.
PA Storage Monitor will monitor very large server disk volumes and report on file age distribution, type distribution, file owners, etc, etc. It will also monitor free disk space, disk quotas, etc. Many different alerts are included.
PA File Sight will help you determine who is reading from and writing to important files. It will tell you when a new file is created or renamed. And, when a file gets deleted, PA File Sight can tell you who deleted the file.
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. Rich reporting too.