Windows XP - No wireless networks found in range

If you get this message no network found in range on a laptop and if the computer got a built in wireless card, then the wireless switch on the computer is off.

If computer got a External adaper then try the following steps
1. disable and enable wlan
2. unplug and replug the adapter
3. reinstall the wireless adapter
4. try change the wireless settings on the router
5. take the laptop to any hot spot and check whether its finding any signal