Public Class Form4

    Private Sub RichTextBox1_LinkClicked(ByVal sender As Object, ByVal e As System.Windows.Forms.LinkClickedEventArgs) Handles rt.LinkClicked
        ' Call Process.Start method to open a browser
        ' with link text as URL
        Dim p As New System.Diagnostics.Process
        p = System.Diagnostics.Process.Start("IExplore.exe", e.LinkText)
    End Sub
    Private Sub RichTextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rt.TextChanged

    End Sub

    Private Sub Form4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'rt.Text = "123"
    End Sub
End Class