This query will detect clients running a Server Operating System

select
SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,
SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,
SMS_R_SYSTEM.Client from SMS_R_System where
SMS_R_System.OperatingSystemNameandVersion like "%Server%"