Xbox lost live connection

I wish someone would come up with an anwser to this problem. Everything was ok with the router. I even purchased a wireless connection for the xbox. Then all of a sudden the wireless failed. We connected it to the router with hard wire, that we used in the past. That connection was working, then it failed. I was told the same as everyone else, call linskys, call optimum, the same BS about the windows not being open, dah, dah, dah. I think this is an Xbox problem, not a router or interent provider problem. How can something work one day and then not the next. People at xbox don't know what they are talking about! Help if you can.