CD and DVD no long displaying contents in Windows Explorer

Hello,

Recently, when I go into Windows Explorer; My CD and DVD drives are not
displaying any list of files.

I have tried all the obvious, ie swapping IDE cables over, uninstalling
devices and reinstalling etc, dumping the firewall and anti-virus software,
uninstalling SP2 and reinstalling. But nothing seems to work. If I boot
the machine with a bootable disk, this works.

I am sure that flattening the machine would solve the problem, but this
seems a bit drastic.

Any ideas?

thanks in advance

Ricky