let me see if I understand your very limited request for information and assume you have an iso file on your pc. Download or use a dvd burning program such as dvd decrypter to load the iso file and burn to disc if the file is larger than 4.7gb use dvd shrink to compress it and create another iso that can be burned using shrink.
just use shrink and let nero burn to disk, you don't need to make another img of the iso, elliot just to let you know shrink dose not burn anything, it just compresses and encodes. good luck happy burning have a nice day
