This Excel Vba Code is to find duplicate values in sheets of workbook. The duplicate records are searched in the used ranges of all sheets by macro :
For syf = 1 To Sheets.Count
Sheets(syf).Select
ActiveSheet.UsedRange.Select
...
Background of found records are painted and new borders are drew :
For Each mycell In Selection
If WorksheetFunction.CountIf(Selection, mycell.Value) > 1 Then
mycell.Interior.ColorIndex = 8
mycell.Borders.Weight = xlThin
mycell.Borders.ColorIndex = 44
End If
Next
If desired the processes can be recovered with "Undo Button".