вот собсна сам текст:
Older versions of Microsoft Windows, when receiving signals from both a wireless network that is broadcasting an SSID and one that is not broadcasting the SSID, will always connect to the AP that is broadcasting its SSID. If such a device is connected to an AP that is not broadcasting its SSID, and another AP is turned on that is broadcasting its SSID, the device will automatically disconnect from the first AP and connect to the AP that is broadcasting.