can someone help me with a nrg file. PLEASE!!!!!!!!!

i have downloaded star wars jedi power battles and it is an nrg file. it is 185 mb so i'm not sure if this is right. but anyways i have 2 questions. One question is if there is a cdi to nrg converter that someone can give me or tell me where to get it. the second question is that i've tryed to burn it with nero 5 and it says it is a foreign image and i don't no what to do. CAN SOMEONE PLEASE HELP ME!!!!!!!!!!! THANKS