what do you mean by "not working"? We need some details before we can offer much in the way of help.
Has the drive ever worked? New drive, used drive, new installation?
Is the drive listed in My Computer and Device Manager?
Some details from Device Manager in DVD/CD Drives and IDE Controllers would be helpful.
Will it read a data or music disk? Will it play a dvd disk?
Please give us some details of the burning problem and if you get errors. What are you trying to burn, ie: avi, mpeg, disk to disk, hard drive to disk. Man give us something to work with here.
If I told you my car didn't work, would you know how to tell me to fix it with the vague details I provided. We can't see over your shoulder to see what's wrong or what your doing so you gotta help us before we can help you.