Updating firmware wrt54g
Find one of those devices and check the IP address configured as the default gateway.Download the firmware that matches the hardware version of the WRT54G router.For all versions of the Linksys WRT54G router, the default password is admin. There's no default username for the WRT54G, so leave this field blank when logging in. If the password on your Linksys WRT54G has been changed, the default password of admin won't work.
Assuming the Linksys WRT54G has been working as your router, you probably have several devices that are connected to it.
This includes everything from the wireless password and network name to any custom DNS servers that were configured, static IP addresses, and port forwarding rules.
If 192.168.1.1 isn't the IP address that's configured for the router, it's less of an issue than if the default password isn't correct.
Since firmware release: 3.x.x from Oct 2004, limited Qo S is now supported by the vendor on all versions of this router.
Cisco/Linksys download page for WRT54G Because this router has Linux based firmware its possible to replace portions of the firmware with custom programming.