Hello & welcome !
I want to install the latest CHDK firmware (g10-103b) which I got using Acid download function.
Is your firmware version really 1.03b ?
Did ACID report 1.03b when you feed it with an image from your camera - or did you just download the g10 build with the "highest" number ?
If so - the camera's firmware version must fit to the CHDK build (e.g. 1.03b) version...
I click yes, than a black monitor will appear and nothing will happen.
When you call the "Firm update" process, do you see the CHDK splash screen ?
If so, just press or half-press the shutter button once to switch to record mode...
If the camera crashes (no response to any keys), most probably the CHDK version does not fit your camera's firmware version.