SOLUTION:
Add a Windows OS to monitor:
1. Login to the Spotlight Cloud Diagnostic Server box and open the Spotlight Cloud Diagnostic Server App.
2. Click on Connections.
3. From the top drop-down menu, select Windows and double-click on "Add new connection".
4. Enter the Address and credentials and click on Test. If the connection succeeds, click OK.
5. In the App, to the properties of the SQL Server connection in question.
6. In the OS details drop-down, select the same Windows OS that was set up, click OK.