Windows 7 comes with built-in wireless management tools that are integrated into the desktop. If your wireless card is disabled, you can turn it on within the Windows Device Manager to allow your system to make use of nearby wireless networks. Enabling this device automatically creates an adapter within the Windows Network and Sharing Center. After Windows has set up the device, it activates and begins scanning for nearby wireless networks.
Open the "Start" menu and click "Control Panel."
Click "System and Maintenance," then click "Device Manager."
Enter your administrative password if requested, then click "OK."
Click the arrow next to "Network Adapters" to expand it, then right-click your wireless adapter. It can be identified by the text "Wireless" or "802.11." Select "Enable" from the drop-down menu. Your wireless adapter is now enabled.