you type in address bar, on internet explorer: 192.168.1.1
It's not always that. Mine, actually has never been that. And I've had multiple routers.
To find your default gateway (Like 192.168.1.1)
Press the Windows key and R at the same time.
Type Cmd, or Command.
Once you get the command prompt, type ipconfig.
Look for the numbers after Default Gateway.
In your internet browser(Internet Explorer, Mozilla, Chrome, etc), in the address bar, then follow the rest of MillCzarr's steps.