Наконец-то разобрался.Использовал пользовательское действие VBScript.
Dim myUpgradeCode
myUpgradeCode = "{6EFB1553-7F4F-4E26-A32B-E2F0F8E11CA9}"
Dim justMe
justMe = False
'AssignmentType
' Equals 0 if product is advertised or installed per-user.
' Equals 1 if product is advertised or installed per-machine for all users.
Set products = Session.Installer.RelatedProducts( myUpgradeCode )
For Each product In products
astp = CLng(Session.Installer.ProductInfo(product, "AssignmentType"))
If astp = 0 Then
justMe = True
End If
Next
If JustMe Then
Session.Property("ALLUSERS") = ""
Else
Session.Property("ALLUSERS") = "1"
End If
и выполнил его перед AppSearch.
Готово!