The following compares Sheet 1 vs Sheet 2 and finds anything in Sheet 1 that was not in Sheet 2.
I believe for your project you'll need to change (in the macro code) Sheet 1 to reflect Sheet 2 .... and Sheet 2 should be changed to Sheet 1.
Code:
Sub compare()
Application.ScreenUpdating = False
Sheets(3).Activate 'Go to sheet 3
Cells.Clear 'and clear all previous results
Range("a1").Select 'set cursor at the top
Sheets(1).Activate 'go to sheet 1
Range("a1").Select 'begin at the top
Dim search_for As String 'temp variable to hold what we need to look for
Dim cnt As Integer 'optional counter to find out how many rows we found
Do While ActiveCell.Value <> "" 'repeat the follwoing loop until it reaches a blank row
search_for = ActiveCell.Offset(0, 1).Value 'get a hold of the value in column B
Sheets(2).Activate 'go to sheet(2)
On Error Resume Next 'incase what we search for is not found, no errors will stop the macro
Range("b:b").Find(search_for).Select 'find the value in column B of sheet 2
If Err <> 0 Then 'If the value was not found, Err will not be zero
On Error GoTo 0 'clearing the error code
Sheets(1).Activate 'go back to sheet 1
r = ActiveCell.Row 'get a hold of current row index
Range(r & ":" & r).Select 'select the whole row
cnt = cnt + 1 'increment the counter
Selection.Copy 'copy current selection
Sheets(3).Activate 'go to sheet 3
ActiveCell.PasteSpecial xlPasteAll 'Past the entire row to sheet 3
ActiveCell.Offset(1, 0).Select 'go down one row to prepare for next row.
End If
Sheets(1).Activate 'return to sheet 1
ActiveCell.Offset(1, 0).Select 'go to the next row
Loop 'repeat
Application.ScreenUpdating = True
Application.CutCopyMode = False
Sheets(3).Activate 'go to sheet 3 to examine findings
MsgBox "I have found " & cnt & " rows that did not exist in sheet 2"
End Sub