Public Class Form1
    Dim t1 As Integer
    Dim t2 As Integer
    Dim t3 As Integer

    Private Sub Timer1_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        t1 += 1
        Iterator()
    End Sub

    Private Sub Timer2_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Timer2.Tick
        t2 += 1
        Iterator()
    End Sub

    Private Sub Timer3_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Timer3.Tick
        t3 += 1
        Iterator()
    End Sub

    Private Sub Iterator()
        Label1.Text = t1.ToString
        Label2.Text = t2.ToString
        Label3.Text = t3.ToString
    End Sub

Public Class Form1
    Dim Flow_1 As New System.Threading.Thread(AddressOf Flow1)
    Dim Flow_2 As New System.Threading.Thread(AddressOf Flow2)
    'Dim check As Integer
    Dim t3 As New System.Timers.Timer(100)
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Flow1()
        Flow2()
    End Sub
    Private Sub Flow1()
        'MsgBox("Поток 1")
        Timer1.Start()
        t3.AutoReset = True
        t3.Enabled = True
        AddHandler t3.Elapsed, AddressOf t3_tic
        t3.Start()
    End Sub
    Private Sub t3_tic(ByVal sender As System.Object, ByVal e As System.EventArgs)
        Label1.Text = check
    End Sub

Module Module1
    Private check As Integer
End Module