First, to avoid opening the box, uninstall the drive, reboot, and reinstall the drive (if possible). If you cannot complete the reinstallation, it seems likely that during the off-time one or more of the connectors on the back of the DVD have slightly corroded with resultant resistant path. If that is the case, then open the box and reseat the connectors on the drive and also the one on the motherboard (I pesume another IDE connector).