Access Denied using MS DOS to Move Files
When you attempt to use an MS-DOS prompt to copy or move files to a CD-R or CD-RW drive for staging, you may receive an "Access denied" error message. This issue can occur because the MS-DOS subsystem is not coded to redirect files from the CD-R.
Details:
http://support.microsoft.com/kb/279118/en-us?spid=1173&sid=global