Tell us about your computer... brand and model...
Have you had the case open recently, or in enough vibration of a move that caused the cables to vibrated out of their slots.
Go to Start->Control Panel->System->Hardware->Device Manager and see what is listed with a red, yellow or grey flag... which can sometimes be a clue.
It is not uncommon for an optical drive to fail after heavy use, or after a year, but it is uncommon for both to fail, so either a cable has become unplugged or something else is setup incorrectly.
It would be helpful to know as much as you can tell us about the computer.
