My PC, Win2k, SP4, will not read cd's from either drive or floppys or a jumpdrive. All devices seem to be recognized by the device manager and are assigned drive letters accordingly.
The floppy is recognized and works if you insert a boot disk.
The jump drive, when inserted, assigns a drive letter to it.
The cd drives, are assigned permanent drive letters, they will not read a cd inserted after the system has booted to the desktop, but will work in two situations - 1)if I insert a cd in the drive and boot to the desktop, that cd works/reads/installs correctly till the drive door is opened, then no matter the drive will not read a cd until rebooted with a cd in the drive. The exception to this is, 2)the cd drives will read an audio cd and auto open WMP and play it.
I have a similar system (same motherboard and memory) with an identical model CDR unit that works ok. It has no floppy or CDRW drives in it.