None of it makes any sense to me. It's like trying to read Arabic or something. What exactly are the steps needed to get CHDK running on my Canon Powershot A550? I did as the wiki says, installed the hack using the simple method. But when I turn the camera on nothing is different. There is also no option to update the firmware either.
The only complete and current documentation on how to get CHDK running is here : Prepare your SD Card
There is a link at the top of that page to the STICK utility. You probably want to use that - its the simplest way to get CHDK installed.
Assuming you've done that, then you need to put the little SD card lock switch on your SD card into the locked position before putting it into the camera. That's all there is to it.