Locate Column that only has one value in excel

ok try this:

Sub FindOnes()
Dim MyRg As Range, CCol As Range, CCell As Range, MyVal, ColC As String, IsDups As Boolean
Set MyRg = ActiveSheet.UsedRange
ColC = ""
For Each CCol In MyRg.Columns
    MyVal = ""
    IsDups = True
    For Each CCell In CCol.Cells
        If CCell.Row <> 1 And MyVal = "" And CCell <> "" Then MyVal = CCell
        If CCell.Row <> 1 And CCell <> MyVal And CCell <> "" Then
            IsDups = False
            GoTo nXtC
        End If
    Next CCell
    If IsDups = True And MyVal <> "" Then ColC = ColC & " " & CCol.Cells(1).Address(0, 0)
nXtC:
Next CCol
If ColC <> "" Then MsgBox "these columns have duplicate values:" & Replace(ColC, 1, "") Else MsgBox "no columns have duplicate values"
End Sub

This works, thanks NickyC. You are awesome!!