If you have recently bought the linksys wrt54gr wireless router you can simply use this default user and pass for the router configuration page as follow. However, if you have forgotton the password that you have set previously, you need to reset your router settings first. To reset the router settins, please refer to the article:
http://nabtron.com/forgot-linksys-wrt54gr-password-how-to-reset-settings-of-the-router/
and once the router is reset you can follow to this method to use the default admin logins to access your linksys wrt54gr wireless router configuration page.
Access the router configuration by typing this in the browser: 192.168.1.1
You will be prompted to enter the user and pass for the router. Enter :
User: (blank, do not enter anything)
pass: admin
These settings should work for linksys wrt54gr wireless router, incase they dont, then use admin for user and admin for password.