How restart a thread, no pause nor sleep

I've searched around and I want to abort a thread and restart it, something who should be really simple but no one is answering.

Basicly I have an user who conenct throught a form, when the user is authenthified it raise an event to connect the user bringing a new form on another thread, so if the user disconnect I end the thread and bring him to the connection form but if he try to connect again how do I start the thread again

Starting connected form

Private Sub sAuthentified(ByVal Sender As Coms, ByVal sTemp As String) Handles mComs.sAuthentified
    If (Equals(Sender.AES_Decrypt(sTemp), "$%?SuccesS&*(")) Then
        Dim d1 As New HideForm(AddressOf Hide)
        Me.Invoke(d1)

        t1.Start()
    Else
        ToolTip1.Show(String.Empty, UsernameField, 103, 10, 1)
        ToolTip1.Show("Matricule et/ou password ne sont pas valide.", UsernameField, 103, 10, 1000)
    End If
End Sub

Ending the connected form

Private Sub Me_Disconnect(ByVal Sender As Coms) Handles mComs.Disconnect
    mComs = Nothing

    t1.Abort()

    connectedForm.Dispose()

    Dim d As New ShowForm(AddressOf Show)
    Me.Invoke(d)
End Sub

Started by t1

Private Sub newForm()
    connectedForm = New Connected(mComs, sUser_sPass)

    connectedForm.ShowDialog()
    connectedForm.Dispose()

    mComs.sendMessage(Coms.enumTags.Disconnect)
End Sub