usb wireless adapter not recognizing router

hi all, i have a wireless issue that i could use some help with. im setting up a old pc for my daughter, its running xp, im using a usb edup 54m wireless adapter to connect to our sky router. the adapter isn't picking up the router, it recognizes all of the neighbors but not mine. drivers are installed and everything else picks up the router, i remember this happening before but cant remember how i got round itany help would be appreciated, cheers

 

not worry, all sorted now. logged in to router and changed`mode to 802.11b only and now all is fine