The maximum file size on a FAT32 formatted partition is4 GB or 4,294,967,296 bytes minus 2 bytes ...NTFS file system has a (theoretical) maximum file size of16 exabytes or 18,446,744,073,709,551,616 bytes (2^64 sectors) ...NTFS system is far better at holding large data files but is more unstable than Fat32...not to mention the DOS compatibility issues it comes with. In your case Fat 32 cant handle a whole image which is more than 4 Gb. The reason behind this is that the full image cant be unrared as it is bound to exceed more when it gets ripped out.So to be more precise what water wants you to do is something like this:1) Doubleclick on the winrar file2) Double click on the DVD Image file [ISO in your case]3) You will see the list of files on the DVD image now. If its a Media DVD then you will see a bunch on .VOB files and if it is a software or a Game DVD then you will see a whole list of lotta programs. Whatever the case maybe its a 99% probability that no file in it would be more than 4 GB. The whole bunch collectively makes it a 4Gb data.4) Simply extract one file after another from the image and then when you have unrared all..put it in one folder and enjoy.