Copy Cat uses a superior method to copy files by using a byte per byte method.
If a byte is unreadable it skips only that byte by default and tries the next one. This can be very helpful if you want to copy data from scratched or partially unreadable CDs or DVDs, partially unreadable hard drives or other media like zip drives as well. It is possible to change the number of bytes that get skipped during the process. The author recommends that 1 byte is skipped but it is possible to adjust that value to 10, 100, 1000, 10000, 100000 and one million.
You loose of course more data if you set that value to a higher figure. Using Copy Cat can’t be easier. Just select a source file from your hard drive, CD, DVD or removable storage and select a destination directory. Adjust the number of bytes that get skipped if you like and click on copy.
Copy Cat then tried to read the file byte by byte and copy it to your destination. This method has no guarantee of making all unreadable files work again. I think it should have nice results with text documents and problems with archives. I had no unreadable files of both kinds and could not test my theory. I still think it is more likely that you get CRC errors with the archives if bytes have been skipped during the copy.