Private Sub Button2_MouseEnter(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button2.MouseEnter
 
        Button2.Image = Image.FromFile("C:\Dokumente und" & _
          "Einstellungen\cs-gast\Desktop\test4\3_big.bmp")
    End Sub
 
    Private Sub Button2_MouseLeave(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.MouseLeave
 
        Button2.Image = Image.FromFile("C:\Dokumente und" & _
          "Einstellungen\cs-gast\Desktop\test4\3.bmp")
    End Sub

c++ umsteiger .... so viel fragen^^