ISO file much bigger than 700MB

HI, i new here. I got the following question.
I have an iso thatis 767MB. I have searched around and learned about raw data and such. However, this iso seems to be 767MB of files only and I tried with nero MOde 2/XA(dont know if its the Mode 2 Form 2 i read about),which asked me if i wanted to use overburning(i had tweaked the expert feautres) but it failed and also i tried with alcohol which didnt even start the burning process(write method DAO/SAO). But it still didnt work. :sad: The iso was Chessbase 9(if it makes any difference).
Can anyone tell me what to do?

If you want to make a backup of this game then I would suggest scanning your original disk with ARay Scanner to find out what copy protection is on it. Then you can use the correct profile in Alcohol to create a new image of the game with the correct settings.