A hard reset will revert everything back to the way it was when the ISP shipped it. Meaning that once powered up, if you then connect your computer to it, it should provide your computer with a new IP addy and auto-configure everything. It should also mean you can access the router config via the 192.x.x.x

Alternatively if you open the Network and Sharing thing in Windows, then click on View Status next to your connection - this should open a little old school Windows property style window, in here click Details. Then on the window that pops-up the IPv4 Default Gateway (or IPv6 if your connection uses that) will be the IP address of your router. You can then type that into your web browser and it should load up your routers setup/admin page and you can tinker around in there.