Contrary to what is mentioned above, YOU DO NOT NEED A BOOT FLOPPY TO MAKE A BOOTABLE CD.
All you have to do is
1. Go to
http://www.bootdisk.com
2. Select the boot disk you want and make sure to download the image (img) format
3. Open Nero Burning Rom, in that click on boot disk, and in the first tab browse to the place you have stored the boot img you just downloaded
4. click new
5. You will now get a file browser in which you can drag and drop whatever file you want
6. Burn baby burn