Before you try to replace that drive you may want to consider cleaning the laser on the drive. Its failry simple, especially since its a laptop disk drive, which are generally made the same and will cost fare less than replacing the drive. Drives tend to go bad after a couple of years collecting dust, simply because of dust covering the lens, impairing its ability to read anything.
All you'll need is;
Some Q-Tips probably one or two.
Rubbing Alcohol. (More Alcohol, less water, the better)
The Following is a picture of my own laptop Disk Drive, view it if you want to get an idea what the laser should look like.
Turn OFF your computer before procedding!
1) Open you disk drive, using the compressed air to remove any lightly placed dust from the drives surface. Give the interiore a blast as well.
2) Take your Q-Tips and slightly moisten them with the rubbing alcohol, if they are dripping wet try to take out some of the moisture. You can use water for this as well, but I highly suggest rubbing alcohol.
3) Take your alcohol covered Q-Tip and gently press it against the laser a few times. Let the alcohol sit for a few minutes and clean up any remaining moisture with the dry end of the Q-Tip. Wait a few more minutes, alowing any alcohol you couldn't get up to evaporate, it dries pretty quickly.
4) Insert a disk and test it out.
5) Downloading and installing new drivers never hurt either.
You'll want to look under CD/DVD and select your operating system above.
If this doesn't work for you or you don't whish to try this at all the best place to look is here. Under parts and upgrades or you could call/email/live chat their tech support.