All files on a CD-R will be read only you can add files if you start a disk as a multi session. Mutiti seesion disks cannot be used on Standalone CD\DVD players untill the disk is "closed" finalised.
If you want to rewrite files to a CD and use it as you would a hard drive then you need a rewrite disk, CD-RW or DVD-RW and use Neros INCD package writing software. Format the disk first and use drag and drop if using Windows XP CD writing software.
These disks will not play on stand alone players either.