Dear friends, recently i got hold of a old laptop may be three or four years old. I already have BSNL a connection and a ADSL modem, ofcourse BSNL supplied. Since the laptop has a wireless LAN built in I wanted to surf internet from it. The local BSNL customer care shop said the wireless modem cost Rs.2,200/- . Then i surfed ebay and flipkart and bought TP-Link 150Mb latest model ADSL wirelss modem for Rs.1800/-. Then I installed it it was working fine. And I could surf internet from my desktop computer and laptop. But after some time the SSID I gave to the Wireless modem does not apprear in my laptop but all other nighbours links showed up. Each time I quick started the modem it appared and again I am able to work the internet. Going deeply into the various configurations and deeply reading the manual and visiting various website does not help. Since my hobby was wireless and Radio I found out the Modem adopted the latest 802.11 n technology besides the older b and g technologies. My laptop adopted the 802.11 a b g technologies. That means in the laymens terms the laptop had the 'a' standard which the modem does not have. And the modem hand the 'n' technology which the laptop does not have. So i went in to the laptops wireless modems configuration and changed it to 802.11 b g and similarly changed the wireless modems wireless configuration to 802.11 b g . Then onwards I am able to work internet from my laptop without any problem, and no restarting require. Though these settings are supposed to be automatic between old and new devices it might happed. with regards -Partha.