Wasted some time on this so here is a quick copy-paste from - http://www.manageengine.com/network-monitoring/help/userguide/monitoring_mssql.html
Monitoring MSSQL Parameters
MSSQL Services and Parameters can be monitored using WMI. Here are the steps to associate the MSSQL monitors to a device:
- Go to the snapshot page of a device that has MSSQL running.
- Scroll down and select the Monitors tab.
- Click on Performance Monitors. The monitors are listed on the right.
- Click the Add Monitor button on the right. A list of monitors is displayed.
- Click the MSSQL Monitors button on top of this list. The monitors of all the MSSQL parameters are displayed.
- From this list, select the required MSSQL Monitors and associate it to the Server.