First of all I agree with COLGeek. However if you are concerned about accidently connecting to one of the other shown networks then the following link may be of some help:
http://www.nextofwindows.com/how-to-block-a-computer-from-accessing-to-a-specific-wireless-network/
Applicable to Windows 8 as I understand it all.
Not at all a complete solution because new wireless networks will probably keep popping up and some will occasionally change their names. I.e., you will probably have to keep updating the blocked list.