Sometimes you want to apply your policy to every client PC in many OUs. To do such you can use WMI filter. This is especially useful in messy AD structures, where is no dedicated OU for client computer objects.
Namespace: root\CIMv2
Query: select * from Win32_OperatingSystem where ProductType="1"
I use here following WMI Class and property:
https://msdn.microsoft.com/en-us/library/aa394239(v=vs.85).aspx#properties
ProductType
Data type: uint32
Access type: Read-only
Additional system information.
Work Station (1)
Domain Controller (2)
Server (3)