Canon PowerShot G1 Firmware Update Installation Instructions page 5

Please verify the following before downloading the archived firmware file.
Please see the inner side of the battery cover.
If you can see a red stamp "2" there, firmware version 1.0.0.3 has already been installed in your
camera.
PROCEDURE 5 : Press the "SET" button
Press the "SET" button to start writing the firmware update.
Precautions :
If you wait more than 5 minutes between Procedures 4 and 5, the camera will cancel the menu
and turn off using its Auto Power Off function when you press the MENU button.
In this case the firmware is not updated. To update the firmware please return to PROCEDURE
2.
Once the update starts, the indicator LED will cycle from
The message shown here will be displayed on the LCD
monitor until the firmware update is complete.
The update will take approximately 90 seconds.
Do not turn the power off during the firmware writing
operation.
Do not open the CF card slot cover or press any camera
buttons during the firmware writing operation.
The indicator lamp goes off and the camera restarts automatically in Replay mode. This completes
firmware update.
You can select [Firm Update] from Play menu after updating.
Once you were successed the firmware update you can not do
again.
The message shown the right will be displayed on the LCD
monitor.
If you wish to use the CF card for taking pictures, initialize the card.
ORANGE to GREEN .