I've changed my ip ad.. And also spent hrs on the phone with my Internet provider.. (sky) thev done everything possible, re-encrypted my account completely and still no access for xbox live... It doesn't evn pass the first hurdle asin (network) .. I ain't too clever with this xbox but this 1 is trauma!! ived tryed everything......... I bought the xbox secnd hand, , 150 its the elite slim 250g and spose be wireless... Could it be the xbox?
Keep it simple, if possible. If you have a separate modem and router (and I know that isn't always the case, many DSL users have a single combo modem+router), then connect the XBOX directly to the modem. If it now works, at least you know it's the router that's causing the problem.
Remember, if you need XBOX Live access, you have to open and forward the necessary ports on your router. See http://portforward.com for the details regarding your router and the XBOX. Or to keep is simpler, you could either enable UPnP (Universal Plug-N-Play) on your router (it may be disabled by default), which allows the XBOX to manage the ports itself, or else put the IP address of the XBOX in the DMZ of the router (in which case, be sure to give the XBOX a static (fixed) IP so it doesn’t ever change once you setup the DMZ).