This report gives you list of PCS where no user logged into the computer since 20 days.If the SCCM clients has any issues in sending inventory information to site server,you will see lot of computers though user logged into the computer.
a.Name0,a.UserName0,TimeStamp from v_GS_COMPUTER_SYSTEM a ,v_FullCollectionMembership b
where DATEDIFF(dd,a.TimeStamp,GetDate()) > 20 and b.CollectionID = @ID and a.ResourceID=b.ResourceID
order by a.Name0
Prompt for ID: SELECT DISTINCT CollectionID, Name FROM v_Collection