installing dvd drives

I have 2 dvd r/w's in my pc that worked perfectly, all of a sudden, they are not recognized in the bios and I can't get them installed, by all the usual methods. In the bios they are listed as unknown and the pc on boot up, looks for hard drives on my secondary drive where they are. My hard drive is on the primary drive not the secondary.
I also get a message that my Windows XP Home Edition is not genuine.
It's 4 years old and I've had no trouble until now. I have a Dell which is out of warrantee and I can't find the problem. Can anyone help. Please.
Pooky98

 

Tried that ddp, no help. What I don't understand is that in Windows, the basic program is supposed to recognize any plug and play item that gets attached before the pc reboots and installs it automatically. My pc shows a dvd r\w as a cd-rom when I connect it singly but doesn't install it.Because it doesn't install it, I can't use the original installation cd-rom. It's very aggravating.Thanks for trying to help.
Pook

 

Thanks for the suggestion ddp. New cable is ordered, will be shipped on the 18th, hopefully.
Pooky

 

Just got the new cable. Installed it, nothing new. Everything the same.It looks like the motherboard.

 

Thanks for your efforts ddp. Can't do it today, will try tomorrow and let you know.
pooky

 

ddp, tried switching cables, one was recognized but it wouldn't install. It looks more and more like mobo.
pooky

 

How about a suggestion. I have no knowledge of PCI cards.
Thanks for your interest.
Pook