On the NB that you logged on with the default setting in Windows is to enter the Settings once and they it will Auto Connect the next time that the NB goes looking for a connection.
To change this you would need to change the way that the NB connects to the Router or at least how the WiFi connection is made.
Also you can log into the Router and specify the number of concurrent connections that you want to allow to prevent unauthorized connections being made.
With any form of Router you need to update the Firmware as often as it becomes available and for safety you should change the Default Password to prevent outside sources attempting to gain access to the router and alter the settings.
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