What would cause your CD burner to stop making good CD's that work?

Possibly a misaligned lens, resulting in the drive writing grooves slightly off line and across tracks. Remedy, take the drive into a technician qualified in repairing such a device (a local representative of the manufacturer) or to the outlet from which you purchased the device originally. Ensure the drive is taken to a capable repair team. This is also a quick fix to most physical cd-drive problems should the drive fall under warranty still. Perhaps seek updated drivers from the manufacturer's website, or www.cdrom-drivers.com (check validity); whilst it is unlikely that this will resolve the issue, sometimes a driver with assured integrity mysteriously corrects other problems. Scan for viruses if downloading from anywhere but the official manufacturers site however, for drivers are integral to system/drive stability - as easily as they can resolve issues, they have the ability to create new ones if a third-party so wishes. Most often a poor burn would be the result of inferior cdr/cdrws. Try to use a reputable brand, such as Sony, TDK, or Verbatim (Mitsubishi). If a noticeable improvement in burning is found, then the problem's cause has been determined. CDRs are thus the easiest and cheapest plausible solution. Finally, ensure all settings are correct - that the correct speed is being used to burn, in regard to the maximum speed the CDR is capable of being written at; ensure the disc is being created correctly and hasn't slipped onto an alternative setting, such as boot disc or audio cd; and that the maximum data capacity is respected and abided by. CDR writing programs that permit over-burning are useful for fitting a greater amount of information on one disc, however, doing so jeopardises a successful read-out write, which in turn could damage the disc, or in the worst case the drive itself (see first suggestion). Hope the answer you required has been given to you :)