Dell :: Is There A Checklist For Wi-Fi XPS 14z

Current problem with Dell XPS 14z wireless connectivity, i have the laptop since January 2012 and all was well until January 2013. Problems started acting after christmas and now I regularly get dropped from the network. And now, my 8Meg broadband service often only gives me 0.1 downloads. I suspect, because some new router/AP device in the area is interfering with mine (which is a zyxel modem, supplied by Irish national telecoms provider, Eircom.)i have done speedtest around the house and when it fails in the sitting room (less than 20 feet from modem), I tend to get better results in the hall (10 incehs from modem).When I view available devices, one or two others get consistently  better strength than mine -- not sure if this is the brand of mod