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Not broadcasting your SSID is about 1997 WLAN security and is like bell bottom pants and Osmond albums, which are also out dated.

Better SSID security involves not using your name for the SSID, unless creating a Hot Spot, not using the physical location of the AP as the SSID, and using a complex SSID. The Windows units are not doing anything other STA's do not need to do in closed networks. They are using active probes to find the AP. When they boot, no matter the location, the SSID will be in their prefered network list. They will try to find it and are vulnerable to probing station attacks, like any other STA. Probing STA's do tell the world what your SSID is.
Try to use non-device based security when you can.
Not broadcasting your SSID will also cause problems for roaming STA's such as VoIP phones.