What sort of problem are you having? You should be able to insert the disc into your disc drive and sit back. It should run automatically and prompt you on screen with what to do next, e.g. open manual etc.
If it doesn't open automatically you should be able to access it via the 'computer' screen which displays all your drives. Click on the disc drive and the disc should run and on screen prompts appear.
If nothing happens then it would appear that you have a duff disc and should contact canon for a replacement.
By the way, you can also download the manual from the canon website. I lost the one I had with my old powershot and just downloaded another.
Thanks for this now sorted did find out i had not pluged my usb lead from my seperate dvd drive in to my computer .i have allso bought a manuel for the g 12 super camera enjoy using . thanks for your reply .