Private Function FindNodeByFullPath(tncoll As TreeNodeCollection, _
        fullpath As String) As TreeNode
 
    Dim tnFound As TreeNode
 
    For Each tnCurr As TreeNode In tncoll
       If tnCurr.FullPath = fullpath Then Return tnCurr
 
       tnFound = FindNodeByFullPath(tnCurr.Nodes, fullpath)
       If tnFound IsNot Nothing Then Return tnFound
    Next tnCurr
 
    Return Nothing
End Function
 
 
Private Sub CompareTreeValues(ByVal tnbase As TreeNode, _
        searchtree As TreeNodeCollection)
 
   Dim tnfound As TreeNode = _
        FindNodeByFullPath(searchtree, tnbase.FullPath)
 
   With tnbase
      If tnfound Is Nothing Then
         .BackColor = Color.Red
         .ForeColor = Color.White
      Else
         .BackColor = Color.White
         .ForeColor = Color.Black
      End If
   End With
End Sub
 
 
Private Function NextNode(ByVal tncoll As TreeNodeCollection) As TreeNode
 
    For Each tncurr As TreeNode In tncoll
        CompareTreeValues(tncurr, trv2.Nodes)
        NextNode(tncurr.Nodes)
    Next tncurr
 
    Return Nothing
End Function

  FillTree("C:\Daten\inimasch2.txt", trv1)
  FillTree("C:\Daten\inimasch1.txt", trv2)
 
  NextNode(trv1.Nodes) 'Markieren der Abweichungen von trv2 in trv1