CD Starting problems

Hi, I have two questions related to CD

Q1. On a win2k Laptop, the CD drive letter is displayed, but no CD
(whatever that CD is) can start or run. As if the drive isn't there at
all. The driver is installed properly.

Q2. Again on a Win2k PC everything works fine except when playing and
Audio CD. I can see the tracks playing normaly but I can't hear the sound.
Knowing that the speakers are well installed and I can hear any other
sounds except those tracks from an audio CD.

Any suggestions please.
Regards