If you can't access your router at all and you've tried everything, I would recommend a factory restore reset. Usually that involves holding down the reset button the router for about 10 seconds. Just make sure you read the instructions from top to bottom first.
Another suggestion, if it hasn't been mentioned, is to go into your network adapter settings on your PC and check the "Gateway" address. This is always the IP address to your router. This is provided that your computer is still connected and functioning on the network.
27/12/2007
Mario and Sonic at the Olympic Games
Gold Coast, Queensland, Australia