Hi bofish, If the system is shipped with a wireless card, it will detect all the wireless networks in range. The unsecured network that you are talking about can be one of your neighbour's. Until you are using your network connection with password on it and security software installed on the system the connection is secured. Please reply if you have any questions.
  I got A new Dell Desktop computer link Up to att Dsl modem and what to safe guard it ,New Xps 8500 has Wi-Fi card built In, no Wi-Fi router. I've found unsecured Wi-Fi signals. How Do I do make sure pc is safe and secure . Please  reply soon?:emotion-11:     My pc is new & was setup by dell     
what My pc my data is safe and secure please help