I know that every time you create a file in Windows XP or earlier that the file uses at least one cluster on your hard drive. Whatever doesn't FILL up the cluster becomes "unallocated" space in the file. That space is filled up with various RAM or other file data because the file system must top off the file and fill it completely. This "slack" data not intended for the file is there on the hard drive but is not read when you open the file for viewing. Only special software can view that data. But, lets say that once the file is created, you LATER DECIDE to burn that file to a CD or DVD. The file that burns to that CD or DVD... are you burning the ENTIRE file (including the "slack" data? I ask this to find out whether or not file recovery software would be able to view the "slack" data on the CD/DVD you just burned.    Whe you USE a burning program to burn files on a hard drive to a CD or DVD, the burning program reads the logical file from the hard drive file system. Data contained in the file slack areas is not visible to the burning application.