Unplug Your ADSL Modem. Then remove Modem Drivers. also remove USB drivers. Delete Temp files. Restart your PC. Install USB drivers and next to modem drivers. It will work. sure.. If not let me know..
Connect to the router and go to the Wirless page. Then you can see Security tab. Select WPA-PSK and pur your own password and secure your wirless connection. Have fun..