XP's support of UDF is just Utterly Deniably Flighty.
Copy that data off, and create a simple CDR or erase a CDRW, record a closed session and it will work.
Light reading at http://aumha.org/win5/a/xpcd.php which should contain all you need to know before you lose all your data.
ONLY closed normal sessions transport well.
Compaq Presario 5102US,1.0ghz w/ 376mb RAM, OS=WinXP SP2. The CDD4801 CD-RW worked fine under WinME OS, but since I changed (not upgraded) to WinXP the CD-RW does not recognize CD-Rs. Master data and music CDs are Okay, as are recorded CD-RWs. In particular are photo/jpeg CD-Rs that were created with EasyCD 4.0 w/ME. The CD-Rs are good, because my laptop has not problem accessing them (it has Win2K). I'm confident the Cdd4801 is Okay, because if I take the time to go back to WinME it works and reads everything again, and I can write to it with WinXP. What the Hey, any suggestions?!