Dim x As Integer = resolution.Width * win.Center.Y / resolution.Height
Dim y As Integer = resolution.Height * win.Center.X / resolution.Width
If win.Center.X > x AndAlso win.Center.Y < y Then
    If win.Center.X > resolution.Width - x Then
        MessageBox.Show("rechts")
    Else
        MessageBox.Show("oben")
    End If
Else
    If win.Center.X > resolution.Width - x Then
        MessageBox.Show("unten")
    Else
        MessageBox.Show("links")
    End If
End If