I backed-up almost 4.4GB of data on to a DVD-R with Nero Express 6. I can see all my files including their name, type, size and date attributes. But when I try to open more than half of them, the corresponding program can not recognize the file type (each generating varying error messages). The files at the beginning of the disc all open without problem, but of course my most important data is at the other end. File types vary (.xls, .doc, .jpg, .wma, .htm, .fla), and files types that open on one part of the disc don't open on another.
I've tried copying the files from the DVD, using a different computer, and using different drives (DVD ROM and DVD-RW) without any success. I downloaded and tried over a dozen different DVD and file repair softwares, but they all "recover" the file in the same state as I can access them through Windows XP explorer. Most of these programs do detect errors on the disc when analyzed.
I'm not just looking for software suggestions, since I've been googling for over 3 days. I'm looking for someone who has had the same problem and found a solution, or is an expert on data recovery.