|It depends on how the rewiteable CD was configured.|
Rewriteable CDs (and CDRs) need to be configured for packet writing before you can treat it similar to a USB or hard drive.
You must have somehow done this before with whatever application you used.
This webpage explains this more in detail:
Google for "UDF writing on XP" if you want more information on this subject. Google is your friend.
Some common "drag-and-drop" or "drive letter access" recording packages that can generate UDF-format discs are:
B's Clip (from BHA)
DirectCD (from Adaptec/Roxio)
InCD (from Ahead)
PacketCD (from CeQuadrat)
RecordNow MAX, MyCD, PrimoCD, and PrimoDVD (from Veritas)
Write DVD! (from Software Architects)
UDF discs can also be generated by "mastering" software, which is available from many of the same software vendors. The Windows XP built-in CD burning functionality (IMAPI) does not generate UDF.
☺ When everything else fails, read the instructions.