Dim posFrom As New Point(10, 10) '// Von Bereich
    Dim posTo As New Point(200, 200) '// Bis Bereich
    Dim lastPos As Point '// letzte Position
    Private Sub Form_LocationChanged(ByVal sender As Object, ByVal e As _
      System.EventArgs) Handles MyBase.LocationChanged
        If (Me.Location.X >= posTo.X OrElse Me.Location.Y >= posTo.Y) OrElse _
           (Me.Location.X <= posFrom.X OrElse Me.Location.Y <= posFrom.Y) Then
            Me.Location = lastPos
        Else
            lastPos = Me.Location
        End If
    End Sub