More than "it doesn't work" is needed for someone to help you.
Did it work at one time and now does not? or has it never worked in Win 8? Does it just not read discs? or is it the drive drawer does not open? What is the status of the drive in the Device Manager? Does it show working OK or does it show an error code (and what is the code)?
it works sometimes n sometimes it dont , when i press the eject button on drive nothin happens and the drive icon in my computer is also missing but sometimes it show the icon and the eject button is also working
Try this(2):
1) Shut down PC.
2) Physically disconnect the CD/DVD Drive.
3) Reboot to Windows with NO DVD drive.
4) Shut down PC.
5) Physically reconnect the CD/DVD Drive.
6) Reboot to Windows with DVD drive.
7) Check Device status.