As it's been asked, have you waited the two hours as told you by the router login?
After you have:
If the login username and password has been changed from what the router was initially set to, you need to track down that information and we can't help you in doing so.
If the initial login information has not been changed, it should be on a sticker on the router somewhere. Provided it's your router, you should have physical access, so looking at that sticker shouldn't be too big of a deal.