If you install some CDR software, or uninstall certain Burning software, or have a CDRW that M$ doen't "Quite" support, You may want to read this M$ article on how to fix the problem...
Most "Disappearing CDRW problems can be fixed if you follow the instructions in this article....
h**p://support.microsoft.com/support/kb/articles/Q270/0/08.ASP
Hope this helps solve a comman problem in XP...
SeeYa