Private Sub Form1_MouseWheel(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles Me.MouseWheel
        ProgressBar1.Value += IIf(e.Delta > 0, +1, -1)
    End Sub
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        ProgressBar1.Value = 50
    End Sub