Can't get ubuntu to boot

[xpygmy]

I have downloaded the ubuntu iso, it is the long support 12.04 edition as the newest one is too big to fit onto my disc.
I have a sony cd-r 700mb disc, I put it in and set it as on live file system (or something similar sounding) I then put the ubuntu iso onto it and then I put the disc into my optical drive and all i get is
"reboot and select proper boot device or instert boot media in selected"

and I have chosen it to boot from my optical drive in the bios.

 

[xpygmy]

Did you burn the ISO or the just copy/paste the ISO onto the disk?

how would i burn it on there?, I just dragged it from the download file.