First you must verify that your router default gateway is 192.168.1.1 (not typo 192.168.l.l or 192.168.I.I) try to find your default router IP Address, step by step how to find router IP Address in this page http://19216811-ipaddress.com/find-router-ip-address
After you have got your valid IP Address, find your default router username and password, I have a list of common router that using 192.168.1.1 for the default gateway.
3Com 192.168.1.1 admin admin
BenQ 192.168.1.1 admin admin
Linksys 192.168.1.1 admin admin
Netgear 192.168.1.1 admin password
US Robotics http://192.168.1.1 admin admin
or you can check your router’s default IP address on this page http://19216811-ipaddress.com