Avoid automatically connecting to wireless network on windows 7

You can open the Network and Sharing Center. On the upper left, click "manage wireless networks". right click the wireless network that is giving you trouble, and choose properties. Uncheck the "Connect automatically when this network is in range".

Do you use a common SSID name, like "home" or "linksys"? Wireless can be rather dumb. We have a person that has a home network called "linksys". when she is in the office, her computer sees a wireless network called "linksys" and connects. However, that network is the building across the street, so she can't get to our network stuff.

We had her rename her how SSID to something much less likely to be duplicated, and that has fixed her problem.

Are you using an Intel Wireless Adapter? If so your wireless adapter has been set to connect to free hotspot automatically. To disable, open Intel PROSet/Wireless Tools (you can do that by searching it on your start menu), under "Intel Wifi Hotspot Assistant" click "Settings" and untick "Automatically Connect to Free Wifi hotspots"