Prova questo

codice:
Public Class Form1

    Dim WithEvents tim As New Timer
    Dim TheLabel As New Label

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        TheLabel.Location = New Point(20, 20)
        TheLabel.Parent = Me
        TheLabel.AutoSize = True
        TheLabel.Text = "Questo è un testo di prova     "
        tim.Interval = 100
        tim.Enabled = True
    End Sub

    Private Sub tim_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles tim.Tick
        Dim t As String = TheLabel.Text
        t = t.Substring(1) & t.Chars(0)
        TheLabel.Text = t
    End Sub
End Class
TheTruster