How to Repair a Damaged ISO File
Although no surefire way exists to repair ISO files, or any corrupted files for that matter, some select free programs can open damaged ISO files, allowing you to save some, if not all, of the files in the ISO image.
Things You'll Need
Download and install ISOBuster.
Open ISOBuster and select "File" and "Open Image File" from the topmost menu.
Select the corrupted ISO image you want to repair and click "Open."
Click on the files in the opened ISO file that you want to save and select "Extract."
Click "Save" and the extracted files will be saved to your hard drive. This amounts to repairing the ISO as all or some of its files have been saved. The ISO itself may work. If not, the files are saved and you can rebuild it with any CD-R or DVD-R burning tool.