1. In house NBN Wi fi Telstra modem. 2. Thanks for the help am using cable at the moment  1. I understand it's just the "one box". However, that just means it's a Residential Gateway ... which is a Modem, Router, and WiFi Access-Point. 2. OK, good. Why not just use the ethernet cable always ? (as it is faster and less troublesome) XPS-8700 is pretty old. If re-seating the WiFi mini-card doesn't help, it's probably fried. They are cheap and you can just replace it.  Also, in the BIOS ... you might have an option to disable the WiFi-card. Flip that On/Off a few times and make sure it's left Enabled.    
Good Morning all. have xps 8700 lost connection to my Telstra modem and now can't find it. It can find 8 other modems. I have a dell laptop that can find modem and like the desktop has worked fine for a long time. I can hotspot the laptop to the desktop and the desktop connects and works fine on the nbn. We have backed up and done a clean install of windows via cloud download as per recovery advice. Same problem the xps still can't see my modem but works ok via hotspot via laptop or phone all connected to the same modem. any way to quick fix for my son.  Apologies can connect the desktop via cable and works fine
XPS 8700, lost connection Telstra modem