I recently installed XP upgrade over 98. Prior to installing, I backed up all important stuff to CD-Rs, using the Adaptec CD Creator and Direct CD, version 4.0 that came with my Phillips CD-RW. Now, some of the CD-Rs that I backed up to, are seen as blank CDs when trying to read / restore the data back to the HDD. I can visually see that part of the CD has been written to, but XP seems to be telling me that it is a blank CD (under Windows Explorer, there is no data on the CDs). Any suggestions?

EZCD 4 doesn't work with windows XP anymore you have to get EZCD5/Direct CD 5 in order to write/read the data on ur CDRW. if you want to copy your data back to your harddrive, try downloading the UDF Reader program from Roxio.com (the new Adaptec EZCD homepage)

Well not all that true I have had them same problem, and I am currently using EZ CD 5 in xp still not able to read old cd-r's. I was lucky I left my system a dual boot C is 98 D is XP so I read the data in 98 and transfer it to the XP partition to access it.

Make sure you have all of the Windows Updates as one of them was supposed to fix that very issue. If that doesn't help, there is a free product called Isobuster that can help read cds that Windows can't. http://www.smart-projects.net/isobuster/

Are you sure that you converted them all to the format that allows Win 95/98/NT/2000 to read them on any machine? If you left some of the CD's in the raw EZCD format, you will only be able to use them if you have EZCD installed. If EZCD 4.0 doesn't work with XP, just convert the discs on a Win 98 machine. All of my discs work with Win XP.