Updated to fix a cut&paste error and now it uses a join.

SELECT Distinct
CS.Name0 as ‘PC Name’,
isnull(CS.UserName0,HCS.UserName0) as ‘User Name’
FROM
v_GS_COMPUTER_SYSTEM CS Left outer join  v_HS_COMPUTER_SYSTEM HCS on  CS.ResourceID = HCS.ResourceID
WHERE
HCS.UserName0 is not NULL
Order by
CS.Name0