Use system restore to a point when everything worked (this can be undone), and see whether the drive read the discs properly. If it does then it is a 'system' problem. If it does not, then it is, as you say, a 'software' problem. Also, use a lens cleaner-those newly created CDs which were not reconized may not have been properly created, and so not reconized by a drive with dirty lens, but may be reconized by one with clean lens, if the data on the CDs are 'clear' enough.
I have a strange yet VERY ANNOYING problem with both my CDRW/DVD drive. Up until recently it was reading cds without any difficulty. Recently, however, it struggles to read CDRs and CDRWs, although only those created recently, although not just from my CD writer.
Basically, when trying to open the CD from explorer, it recognises the disc (XP says its a CDR) and spins up etc, but then I cannot view the contents of the disc, it just says 0 bytes free, 0 used etc and says file type is RAW. HOWEVER, when I go to Computer Management --> disk Management, the Disc Title is recognised. I then click on it, then refresh the explorer window of the CD and lo! There it is, and all the files are accessable. It then works until I eject it.
Incidentally, if i startup XP with the disc in the drive it recognised it no problem, until again I eject and reload, and I have to go via disk management to 'unlock' the disc.
DVDs can be played and are recognised with no problems.
I thought this might be a problem with the CD writer, although a) all the discs work fine on other PCs, and b) I found the same problem with discs written by someone else.
Also, I have another CDROM drive, and this throws up errors when reading these newish CDRs stating the disk is not formatted. However, disk management solves this again.
It is clearly a software problem, as i discovered when I used Daemon Tools to mount a .bin file and emulated a CD drive. Initially, it threw up the same error as my 2nd drive (disk not formatted etc). However, disk management solves this.
This is driving me mad. Any ideas?!!

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