.
Code:
Option Explicit
Sub Dups() 'Compares data Sheet1 & Sheet2 ... Highlights dupes on Sheet2
Dim Rng As Range, Dn As Range
With Sheets("Sheet1")
Set Rng = .Range(.Range("A1"), .Range("A" & Rows.Count).End(xlUp))
End With
With CreateObject("scripting.dictionary")
.CompareMode = vbTextCompare
For Each Dn In Rng
.Item(Dn.Value & Dn.Offset(, 1).Value) = Empty
Next
With Sheets("Sheet2")
Set Rng = .Range(.Range("A1"), .Range("A" & Rows.Count).End(xlUp))
End With
For Each Dn In Rng
If .exists(Dn.Value & Dn.Offset(, 1).Value) Then
'Dn.Resize(, 2).Interior.Color = vbYellow
Dn.Offset(0, 2).Value = "True"
Else
Dn.Offset(0, 2).Value = "False"
End If
Next
End With
End Sub