I’ve a ubuntu 12.04 bootable usb. but i want to keep a live CD of the same. please tell me how to burn a live CD from bootable usb.
Try this. Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:
Note: Make sure that you replace the X with the right device number.
Once you have the ISO file, you can burn it to CD. On a personal note, I would recommend that you download the ISO from Ubuntu if that is all possible, and burn the CD that way.