Private Sub OnMouseHover(sender As Object, e As EventArgs) Handles Button1.MouseHover
        Form2.Show()
    End Sub
 
    Private Sub OnMouseLeave(sender As Object, e As EventArgs) Handles Button1.MouseLeave
        ' Hay que liberarlo, con un form2.close o form2.hide solo conseguiremos que se centre la primera vez!
        Form2.Dispose()
    End Sub
 
#Region " CenterForm function "
 
    Function centerForm(ByVal Form_to_Center As Form, ByVal Form_Location As Point) As Point
        Dim pLocation As New Point
        pLocation.X = (Me.Left + (Me.Width - Form_to_Center.Width) / 2) '// set the X coordinates.
        pLocation.Y = (Me.Top + (Me.Height - Form_to_Center.Height) / 2) '// set the Y coordinates.
        Return pLocation '// return the Location to the Form it was called from.
    End Function
 
#End Region

    Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.Location = Form1.centerForm(Me, Me.Location)
    End Sub