The test I've used for years is to try it without the router. If that works I suspect the router.
-> Are you using the router defaults and not hiding the SSID (in other words, the stuff we put at the top of the Cnet Networking forum.)
About a week ago we started losing our broadband (cable) internet connection 5-6 times a day, and the only way to restore it is to shut down, turn off the power and then restart everything. We're assuming the problem is either with our provider box or our router. Is there a way to tell which one is the problem without first buying a new router or spending time with the provider trying to get a new box?