Isobuster might work. If the data is actually properly written to the CD, and it’s just the finalization that is missing, he might be able to recover it all.
Others might have other recommendations, I’m sure there are several programs that will do this. I think the Freeware version of Isobuster should work though.
If you have a CD-writer (not just a CD/DVD-player), try reading his CD on YOUR computer using Isobuster. If that fails, he could try recovering the files, especially the jpegs, from his hard drive. Even if Windows is re-installed, if he hasn’t performed a full format many of the files might still be on the drive.
To recover these files, he should NOT install any new programs on the drive, but instead put that drive into another computer which has recovery software (such as Easyrecovery or free alternatives) installed. Then scan his drive and hope for the best. But, with luck, using just Isobuster is enough.