If you want to set up your Linksys routers then follow this blog How to Set up a Linksys Wireless Router which i have discussed in same blog.
Step1: With all connection made, you will now need to login to the router via your web browser. Type http://192.168.1.1 and hit enter. You should see the login screen. Leave the username blank and type admin as the password and hit enter.
Step2: Configure your Internet connection settings on the Internet Setup page that appears. For most users, the default configuration is appropriate. If you have a static IP address, click the Internet Connection and type the information your Internet service provider, provides you into the Internet IP Address. Subnet Mask, Gateway, and DNS boxes, and click Save Settings.
Step3: Change the time on your router by clicking the Time Zone box on the default Internet Setup page,click on your time zone in the list and Save Settings.
Step4: Configure your WRT54G wireless network settings by clicking the Wireless tab at the top of the Linksys configuration page and clicking Wireless Network Set a mode for your wireless network by clicking the Wireless Network Mode box and clicking an option in the list; click Mixed for best interoperability with a variety of devices. Type a name for your wireless network into the Wireless Network Name (SSID box and click Save Settings).
Step5: Set wireless network security settings by clicking the Wireless Security tab under Wireless Set the router encryption to the most secure setting by clicking the Security Mode box and clicking WPA2 Personal in the list. Type a password for your network into the Shared Key box and click Save Settings. The password must be used on every device accessing your wireless network.
Step6: Change the router password by clicking the Administration tab at the top of the WRT54G configuration Web page, typing a new password into each Password box to the right of Local Router Access on the page and clicking Save Settings.
After configure your linksys WRT54G then you can set your router admin password.To more about router admin password or how to set password then follow this article. How to Reset Admin Password in a Linksys Router.
Note: If you are not able to solve this problem or given steps is not giving the proper result or if you need linksys tech support then you can reach online technical support service desk of V tech-squad at their Toll Free No +1-877-452-9201.