case of the disappearing D:\ drive

after installing a creative video card in my AMD 800 t-bird.
When I rebooted I now do not show a D:> drive (CD drive) in either “my computer” or Explorer”
Now the Drive worked fine prior to the new hardware install.
Further more at times it just shows up!
This does not make sense to me. I have heard of this thing happening when a box is taken off the network and cards are removed and there is a lot of disruption to the system.
What can i do besides remove the new hardware. and is there a reason why it is Hidden/gone?