I've been asked to help restore files that were on a CD-ROM at one time but that don't appear to be there anymore. This CDROM contains the only copy of about one year of scientific studies. Is there any way to find these files? The CD-ROM is in read/write format.

Some time ago, I faced a similar problem when someone asked me to recover a CD-ROM that contained a year's worth of research data. The solution depends on the cause of the problem. If the files are corrupt, you can't retrieve them. In this case, too many files had been placed on the CD-ROM, and they started overwriting the data. I used an application called CDRoller (http://www.cdroller.com), which worked well. The application read the CD-ROM, and I was able to retrieve about 80 percent of the files by copying the files to a local drive on the computer. CDRoller can retrieve data files, auditory files, and photo and video clip files. The small shareware fee for the application, which is necessary for data recovery, was well worth it because I was able to save almost the full year of experimentation data. Why folks don't keep multiple copies of such data is beyond my understanding. You can easily store data on a USB memory stick or even on a hard disk, then copy it to a CDROM if you so desire. Backups are essential in my opinion, especially if you can't afford to lose the data.