The Operating System Layer
This layer measures the health of the Windows OS on which Microsoft RDS operates. Typically, all the tests mapped to the Operating System layer of any managed Windows server in the environment will be mapped to the Operating System layer of a Microsoft RDS component as well. To know the details of these tests, refer to the Monitoring Unix and Windows Servers document.
The only additional test that runs at the Operating System layer of the Microsoft RDS component is the Grid GPUs test.