Try pushing the eject button of the drive. Normaly on the right side.
From Windows explorer, right-click the drive and sellect "Eject".
Look at the front of the drive. You'll find a small, unlabelled hole, just the right size for an un-bent paper clip.
Usualy situated somewhat on the left of and over the activity LED. If there is a volume wheel, it's probably just over it.
Un-bend a normal paper clip and push into that hole. It should slightly open the tray. You can now gently pull the drive's tray out.
Once it's open, push the eject button, it should slide in and out. If it don't move, there is another problem:
There is also the possibility that the drive actualy became disconnected.
Open the case and check that both the power and data cable are properly connected.
If it's correctly connected, then it can be that the drive is dead. You need to get a new one. They are cheap, especialy if you can get an OEM version without the manuals and bundled softwares that you already have, and without any fancy, and costly, packaging.
Electro, September 2011