Hi Boddu,
I found a similar problem answered on the Sony VIAO website:
"In Win8, wireless is controlled by the Windows OS. You don't need VAIO Smart Network with Win8. Uninstall it (if you have it).
Then, open the Settings charm in Win8, click the PC settings link at the bottom, click "Wireless" in the settings window, and turn on your wireless. From the Settings charm, you should find an icon that says 'Available' when your WiFi is on and there are available networks. Just click on the 'Available' icon and select the network you want to connect to."
**Also make sure that the wireless adapter is actually turned on. This is sometimes a button or switch on the outside of your case! If there isn't a button on your case that controlls wifi, you can:
"Go to Win8 search charm, type in 'Device' without quotes, and click the Settings filter in the search charm to find Device Manager and start it up. In Device Manager, check under the Network adapter category, find your WiFi adapter, and right click it. If you have an option for 'Enable', click on that. Then you should be able to turn on wireless.
Link to the thread if you're interested:
http://community.sony.com/t5/VAIO-Software-Other-Operating/Vaio-Smart-Network-amp-Windows-8/m-p/30102/highlight/true#M83