Do you still have your previous router ? Or failing that, can you borrow one from a friend for an hour or two, or even go round to a friend's house and connect through their router ? If the problem goes away when you connect through a different router, then the problem is almost certainly with your router, if it is still freezing, then the problem is almost certainly with your laptop.
If this indicates that the router is at fault, then all you can do is check the that router settings are correct in its control panel. If they are, and it is still causing freezes probably your only cure is a new router.
Mind you, I can't think of anything a router would do that would freeze a computer on such a regular schedule, and Win 7 is a pretty robust operating system.