What is the difference between pc cd-rom and pc dvd rom?

For some reason my pc no longer recognizes my cd-rom or my dvd-rom can anyone help me?

• I recently bought a dvd-rom drive for my pc because I thought my cd was broken. Not long after installing the dvd drive it stopped working also. I have tried reinstalling both of them physically and they are recognized for a short period of time but are soon gone once again. Any suggestions would be much appreciated.

• Answer:

  In my experience, your 'drive controller' interface may be faulty. If it's inboard, be sure your drive cables are good, and that you're using the nice clean new cable from your DVD-Rom box and not the one already in your system (If it means unplugging your other drive, do so and reconnect it on the same socket position as the old cable used... If the cable is bad, and your hard drive in linked in the same cable, then you would be experiencing the same issues with your hard disk: random booting/halting, misreads, programs failing to run. If they are on the same cable (HD and DVD) and your hard drive is fine, then this would NOT be the case. Also, be sure your jumpers are correct: if your hard drive is on CS (Cable Select), use CS, if one is master, make the other slave, or if no jumpers are on the back, check your user manual for the Drive to ensure everything is okay. When your jumpers are in, visit your BIOS screen (during bootup) and make sure your BIOS can read the drive. If it can't find it, neither will Windows. If the drive is visible in your BIOS Screen, it's likely to be software related: make sure Windows knows which IRQ and DMA Address it resides at. Yes, it's barbaric and so 80286, but sometimes it's the only way to get the thing working. I'd call tech support/your friendly neighborhood PC nerd for a second opinion if this is the case.