I have solved the problem by myself. To do this, first you have to disconnect your Ethernet cable from your laptop and follow the steps: Start>Control Panel>Network and Sharing Center>Manage Wireless Networks and remove all wireless connections by right click on it and select Remove network from the drop down menu. After doing this, close the windows and scan for the Wi-Fi networks. Click on the available network and select connect. After a while, you will be asked to give a password for your Wi-Fi connection. Type the password and click on connect button. And now will be connected to your Wi-Fi network via wireless.
May be it will help you.
Regards
MD. MAHMUDUL HASAN