Cant find my cd need to install - Linksys Wireless-G WRT54G Router

Here you can get your software:

http://homesupport.cisco.com/en-us/wireless/lbc/WRT54G

Please ensure you select the correct hardware version as not all downloads are compatible with your device.

Step 1:
Flip the device over.
Step 2:
You should find the model number on the sticker underneath the device. Please see the example.
Step 3:
Take note of the exact model number and version of your product. The serial number is located right underneath the model number. In this example, the model number of the device is M20.
NOTE: The images may vary depending on the exact model number of your Linksys Product. If there is no version number besides the model number it means that is version 1.

Hope this will help.