This article is from the CD-Recordable FAQ, by Andy McFadden (email@example.com) with numerous contributions by others.
If you write files to a CD-R with conventional recording and then try
to copy them back, under Windows the files will all have their "read
only" flags set. This can be annoying for documents you want to update.
The files aren't written to the disc as "read only". There isn't any such
permission flag in the filesystem. They're simply presented that way
by Microsoft operating systems. Mac OS deals with this in a nicer way,
showing unlocked files on write-protected media, rather than the dopey
Microsoft approach of showing write-protected files on unlocked media.
You can avoid this situation entirely by using packet writing (where
you just copy files to the disc like a big floppy, e.g. with DirectCD),
which preserves the file attributes, or by using backup software, which
will restore the files to their original state. Stuffing the files into
a ZIP archive works too, but may be less convenient than other approaches.
If you've already got the read-only files, changing them back to read-write
isn't too hard. Some approaches:
If you're using Win2K or WinXP, right-click on the top-most folder(s),
and un-check the read-only box. You will be asked if you want to apply
the change to all files and folders in the folder. Say "yes".
For DOS or older versions of Windows, from a DOS prompt run "ATTRIB -R *.*
/S" on every subdirectory with read-only files in it.
If you prefer a Windows application, try "ReadOnly" from
http://www.sente.co.uk/downloads.htm. They also have a more sophisticated
application called "FlagRASH".
If you can boot into Linux, you can fix non-NTFS partitions easily. Use su
to become root, mount the volume as vfat, cd to the directory in question,
and do "find . -print0 | xargs -0 chmod +w" to enable write permission for
all files in the current directory and in all subdirectories. If you've
got an older version of the file utilities that don't support "-0", you
can use "find . -print | xargs chmod +w" instead, but that isn't as good
because it doesn't correctly handle spaces in filenames. (Of course,
if you're a Linux user, you could just use mkisofs with the appropriate
options and have Rock Ridge file permissions that match the originals,
but this is a Windows question.)