Your company has a wireless network for its small office network. The wireless network does not broadcast its service set identifier (SSID). You configure a user's Windows Vista computer to connect to the wireless network by manually setting the SSID. You need to ensure that the user's computer does not send probe requests to discover if the wireless network is in range. What should you do?

make sure that the "Connect even if the network is not broadcasting" is cleared

Explanation:

Based on the information provided within the question it can be said that in order to ensure this you should make sure that the "Connect even if the network is not broadcasting" is cleared. Otherwise this option will send probe requests in order to discover if a non-broadcasting network is in range. Therefore by clearing this option no probe requests will be sent.