As ISO file of a DVD movie generally is more than 2GB which exceeds the file capacity of FAT32 file system. If you fail to create ISO file on FAT32 file system, please try below methods:
a. change your FAT32 file system into NTFS;
b. give up creating ISO file, just backup the source movie as a normal DVD movie folder on your hard disc;
c. burn to DVD-R/RW disc directly.
You can select either one of below methods to convert FAT32 into NTFS file system, thus you will create ISO image file in your system without any limitation:
1. Run [All Programs]->[Accessories]->[Command Prompt], type “convert/?”, then follow the prompt to type convert x: /fs:ntfs” (x is the drive letter that you want to convert to NTFS).
2. Select a hard disk, move and backup all the data under it to another hard disc space, then right click the desired hard disk volume letter, run “Format” and select File System as “NTFS”.