Is it Distinct Version Numbers on just the Program?
SELECT DISTINCT
arp1.DisplayName
,arp1.DisplayVersion
FROM
Inv_AddRemoveProgram arp1
WHERE
arp1.DisplayName LIKE '%Visual C++ 2010%'
If not you could try
SELECT *
FROM (
SELECT
arp1.DisplayName
,arp1.DisplayVersion
,arp1.InstallDate
,c1.NAME AS 'Computer'
,id1.[OS Name]
,id1.[OS Type]
,ROW_NUMBER() OVER (PARTITION BY arp1.DisplayVersion ORDER BY arp1.DisplayName) as RN
FROM
vRM_Computer_Item c1
JOIN Inv_AddRemoveProgram arp1 ON c1.Guid = arp1._ResourceGuid
JOIN Inv_AeX_AC_Identification id1 ON c1.Guid = id1._ResourceGuid
WHERE arp1.DisplayName LIKE '%Visual C++ 2010%'
) a
WHERE a.RN = 1;