DLA enables you to drag-and-drop files to and from a CD, burning in 'real-time,' using the CD as if it were a floppy or zip disk. This isn't supported by Windows XP by default, or most other burning software.
The downside to DLA is that it can only be used on a CD that has been formatted specially for DLA. If the CD has not been formatted for DLA, you'll be unable to burn anything to the CD using DLA, receiving that error message when you try to. Also, the option to "Copy to CD" will not be available since DLA cannot perform the function on a non-DLA formatted CD.
Assuming that DLA has already been enabled on the drive for the user in question, what you must do is right-click the burner in My Computer and select Format. **Note** This will permanently erase anything/everything on the CD. It takes about 20 minutes for me to format a CD, but only 5 to format a DVD. Once the CD has been formatted, full functionality should be available.
Now, sometimes DLA glitches, where a previously-formatted CD is not recognized as such. If/when this happens, the CD is still readable, but you can no longer modify anything on the CD or add new files to it. To resolve it, you must copy any/all files to your hard drive, format the CD, then copy all of the files back to the CD.
Hope this helps,