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Rather than assigning computers to computer target groups on the WSUS server, you can assign computers to computer target groups in WSUS using the Group Policy with a feature called client-side targeting.

A group policy object is created and linked to the OU that contains the computers. This group policy object is then associated with one or more WSUS computer target groups. When the computer connects to the WSUS server, it declares these groups to the server and receives the updates assigned to those groups.