Comparing Two Excel Workbooks & Output any differences

Hi experts,

I am new to the forum, Nice to see a good community with so many experts of Excel programming & Macros,

I want to compare two excel workbooks with multiple worksheets each having alphabets, numbers, texts in old file and new file.
The names and order of sheets in old and new file is always the same just some data changes everyday and i want to check on daily basis which data has changed or there is no data changed at all.

Below is the code that i am currently using and i have taken this code from external internet content,
The problem is when i run this code it says unable to find file "olddata.xls" please check the path or correct the filename.

Can you please help me to complete this operation?

' compare an old new to a new file using column B from each worksheet in the two workbooks
' if the old file contains a row that is not in the new file, then add the old data to the
' end of the new file.
' this assumes that the worksheets are all in the same order
Sub CompareandMerge()

    Const oldFile As String = "olddata.xls"
    Const newFile As String = "newdata.xls"

    ' open the two workbooks
    Dim oldBook As Workbook
    Dim newbook As Workbook
    Set oldBook = Workbooks.Open(oldFile)
    Set newbook = Workbooks.Open(newFile)

    ' loop through all of the worksheets assuming both workbooks have the same number
    ' of workheets
    Dim i As Long
    For i = 1 To oldBook.Worksheets.Count

        Dim oldSheet As Worksheet
        Dim newSheet As Worksheet
        Set oldSheet = oldBook.Worksheets(i)
        Set newSheet = newbook.Worksheets(i)

        ' loop through all of the rows of the old sheet and insert missing rows at the end of the
        ' new sheet
        Dim oldRow As Range
        Dim newRow As Range
        Dim newRowCounter As Long
        newRowCounter = 1
        For Each oldRow In oldSheet.Rows

            ' stop when there is nothing in column B
            If (oldRow.Cells(1, "B").Value = "") Then
                Exit For
            Else

                ' get the new data at row newRowCounter
                Set newRow = newSheet.Rows(newRowCounter)

                ' compare the old data to the new data
                ' if not equal, copy the current old row to the end of the new sheet
                If (oldRow.Cells(1, "B").Value <> newRow.Cells(1, "B").Value) Then

                    Dim theNewRow As Long
                    theNewRow = newSheet.Range("B:B").Rows(newSheet.Range("B:B").Rows.Count).End(xlUp).Row + 1
                    oldRow.Copy newSheet.Rows(theNewRow)

                    ' hihglight the new row
                    With newSheet.Rows(theNewRow)
                        .Interior.ColorIndex = 6
                        .Interior.Pattern = xlSolid
                    End With

                Else    ' increment to the next new row
                    newRowCounter = newRowCounter + 1
                End If
            End If
        Next oldRow
    Next i
End Sub

Originally Posted by 6StringJazzer

Is the file with the macro in a different folder than the files you are comparing? If so you need to give the full path name for the files you want to open, similar to this:

Const oldFile As String = "C:\My Documents\Data\olddata.xls"

It is usually a good idea to use the full path names regardless, to avoid any ambiguity about what's going on.

Thanks for your kind support, The files were't located in Macro's folder,I would try this way.
Cheers.