Your Network Administrator is Blocking Access to Certain Networks
If Windows does not detect a network that you think is in range of your computer, it could be because your network administrator is blocking access to certain networks.
If you are on a corporate network, your network administrator might be using Group Policy to control your access to wireless networks. If you think there are wireless networks in range of your computer that are not visible or that you cannot connect to because your network administrator has blocked access to them, contact your network administrator for assistance.
Note: This information provided by Microsoft.