How to Upgrade Linksys WRT54G Wireless Router Firmware

Upgrading Linksys WRT54G Wireless Router Firmware is a quiet simple process. As long as you have the correct firmware, there won't be any complicated process.

1. Backup!

Keep in mind, for any devices firmware upgrade, backup your configuration. It will save tons of time if something goes wrong.
Open your wireless admin page website. By default, the address is 192.168.1.1, username & password is admin. Go to Administration > Config Management > Backup > save the file to your computer.

2. Download firmware align with your wireless version

Flip your wireless router, version model can be found. In the sample below, is version 4.

Go to linksys support website, download appropriate firmware. Ensure you download the correct version.

3. Upgrade Firmware Process

Open your wireless admin page website, go to Administration > Firmware Upgrade.
Click on Choose File, and point to file downloaded in point 2.

Press Upgrade!

The process will take around 1-2 minutes. Ensure your device is not interrupted during process!

On picture below, can be seen the version is upgraded from v.4.20.7 into v.4.21.5:

4. Check your configuration.

If all went well, your previous configuration will be retained after upgrade. However, if the configuration become blank, you can restore the configuration based on file on Step 1 you've done.