Private Function SingleInstance() As Boolean
    Dim m_Mutex As System.Threading.Mutex
    Dim m_UniqueIdentifier As String = Application.ExecutablePath.Replace("", "_")

    m_Mutex = New System.Threading.Mutex(True, m_UniqueIdentifier)

    'This is the first instance
    If m_Mutex.WaitOne(1, True) Then
        Return True
    Else
        ' Not the first instance!!!
        m_Mutex = Nothing
        Return False
    End If

End Function