I was fixing a very old Windows XP laptop from HP with Intel Wireless Pro 2200BG yesterday and despite all the efforts, I couldn’t get the darn thing to connect to my Linksys E4200 router with latest TomatoRAF firmware. Network was visible, I could try connecting to it, but it was either just connecting to it for very long time and then nothing happened. Connecting window just disappeared and that was it. I just felt it has something to do with the router configuration and the age of Intel’s wireless module inside laptop. And after I changed the WMM, laptop connected to my wireless network without any problems. After checking the internets later, it turns out older Intel wireless chipsets have problems with newer routers that use WMM function to prioritize multimedia content over the Wi-Fi connection.
So, if you have to connect an older Intel wireless device to a newer router and it refuses to connect even though all seems fine, try disabling WMM on a router first. That should do the trick🙂