Private Sub Form1_LocationChanged(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.LocationChanged
        Dim screenheight As Integer = Screen.PrimaryScreen.WorkingArea.Height
        Dim screenwidth As Integer = Screen.PrimaryScreen.WorkingArea.Width
 
        If Me.Bounds.Left < 0 Then
            Me.Left = 0
        End If
        If Me.Bounds.Top < 0 Then
            Me.Top = 0
        End If
        If Me.Bounds.Bottom > screenheight Then
            Me.Top = screenheight - Me.Height
        End If
        If Me.Bounds.Right > screenwidth Then
            Me.Left = screenwidth - Me.Width
        End If
    End Sub

fg viperbone