If you would like to monitor additional SQL Server instances beyond the limits of your existing license, contact IDERA Sales to purchase additional licenses.
Once you receive a new license, open the License Keys window by clicking Help > Manage Licenses. Type your license key in the available space, and then click Enter. Your new license lists the number of additional SQL Server instances that you can monitor by SQL Diagnostic Manager. Each new license you add to SQL Diagnostic Manager adds to the total number of SQL Server instances that you can monitor.
To get a new license, contact your IDERA Sales representative.