Powerbook G4 won't boot mounted img on 10.3.9?

[Razeth]

I copied an iso for Tiger (legal copy) onto my PB's HDD and double-clicked the img file, at which point the computer mounted the image automatically. I could access the mounted drive and see it on my Desktop. When I clicked the "Install Mac OS X" icon, it told me to reboot for the installation of the new OS to begin. However, at startup it powers on as normal without the supposed installation. Also noteworthy is that the mounted drive disappears when the computer reboots.

I've tried changing the file extension to .cdr, .dmg, and even .img, and holding down C and option to no avail. Am I doing something wrong? Do I HAVE to have a CD to install the OS or can I use a mounted img?

Thanks for reading guys!

 

[simsaladimbamba]

You have to burn the .iso to a CD or four, as the .iso file is only readable by the OS, thus you can't boot from the file.

 

[Razeth]

You have to burn the .iso to a CD or four, as the .iso file is only readable by the OS, thus you can't boot from the file.

I used Nero 8 to burn a .toast file onto a CD (renamed the extension to .iso). It didn't burn right and came out as just a iso ON the CD. I'm presuming I did something wrong with Nero. Could someone step me through burning the iso with Nero 8 in as newb instructions as possible please? I have one CD left, so I have to make this count. I burned an ISO before with a Linux OS and it wouldn't boot from my Powerbook G4. I'm told I have to convert it into DVD or something for it to boot?

I'm so confused...

Thanks for the reply simsaladimbamba!