It sounds like your computer is searching for an access point to connect to. This may be due to the following reasons: 1) location – could just be out of range 2) there are multiple wifi networks, and it could be scanning them one by one 3) if you do not have a password or passphrase set on your wifi network, then others should be able to see it as well.
Some hidden points that may lead to this issue:
- Does the customer have other wireless devices? What type? How close together are they currently located? Could other devices interfere with the signal reaching their laptop?
- Is there another device operating on the same frequency as the router (cell phones and microwaves use Wi-Fi.