Optical Drives

Hello,

I got a problem with my CD/DVD drives on my desktop computer and would appreciate any help you could provide me with.
My XP SP3 computer was working fine with two CD/DVD drives, one Sony and one Plextor.
Following a graphic card failure I have to install another (an old one : nVidia GeForce4 TI 4600) I’ve also downloaded its latest driver from nVidia (2006).
The problem is my two drives now only recognize CD discs but no DVD discs!
What could be the problems and what can I do?
Thank you in advance.