Are you totally certain it`s not hiding in the device manager ?
Even if it`s got a problem,it should be listed somewhere.
If you find it,uninstall/remove it.Also,uninstall any CD sofware from Add/remove progs or wherever.Then restart computer.If you`ve got a CD with drivers for the drive,use them.
If you can`t find anything in the device manager,I can only think it might be a cable/connector/jumper problem.