I have had people bring me 1 or 2 computers that had this problem (CD
disappeared) and I was able to resolve it by purchasing an IDE
Controller card like the Promise PCI Ultra 100 and then I moved the the
cd drive over from the motherboards IDE controller  to the PCI IDE
controller card.

I have used this card for new computers that I put together too and
their is a dramatic increase in the speed of the hard disk drive.
Before using it, I was copying a 640 megabyte file into a folder on the
same disk drive and it took 2 1/2 minutes and after installing the
Promise IDE controller it was about 1 1/2 minutes.

I did run into some problems one time with moving an existing hard disk
drive from the IDE Controller on the motherboard to the the Promise IDE
controller and I lost all the data on the drive so make sure that if you
are moving an existing hard disk drive that you back it up first!  Just
in case you run into problems!

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