Всплывающее окно через каждые 30 мин

    Dim TopA As Integer
    Dim ScreenH As Integer
    Dim ScreenW As Integer
    Private Sub Button15_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button15.Click
        Form2.Show()
        TopA = (ScreenH - Form2.Height)
        Form2.Left = (ScreenW - Form2.Width)
        Form2.Top = ScreenH
        Timer14.Start()
    End Sub
    Dim TopN As Integer
    Private Sub Timer14_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer14.Tick
        TopN = Form2.Top
        If TopN > TopA Then
            Form2.Top -= 4
        End If
    End Sub

Dim a As Integer = 0
    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
 
        Timer1.Start()
        Timer1.Interval = 30000  '1 секунда 1000
        a += 1
        If a = 2 Then
            a = 0
            Form2.Visible = True
        Else
            Form2.StartPosition = FormStartPosition.CenterScreen 'позиция Form2
 
        End If
 
    End Sub

Dim a As Integer = 0
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        a += 1
        If a = 2 Then
            a = 0
            Form2.StartPosition = FormStartPosition.CenterScreen 'позиция Form2
            Form2.Show()
        End If
    End Sub
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Timer1.Interval = 3000  '1 секунда 1000
        Timer1.Start()
    End Sub