Disk Space Monitor
The Disk Space monitor is simple to setup. You just add the drives that you want to monitor and the alert threshold (as an absolute size or as a percentage of the total disk size). You can also monitor specific folders if they are a volume mounted from another server / device.
When monitoring remote drives it is important to remember that the monitoring service will probably run as a different user than you are currently logged in with, and will most likely not have network drives mapped. The best way to specify a disk in this case is via UNC paths.
The Add, Edit and Remove buttons on the left will let you change the disks that are being monitored.
Like all monitors, this monitor has standard buttons on the right for Adding Actions, setting Advanced Monitor Options and setting the Monitor Schedule.