Sony CRX300E CD-RW/DVD-ROM Combo - DVD doesn't read
do you have software/program that supports DVD.
Try a different DVD/Movie/Disk or alternative.
Also install a program, such as Nero which will give you physical characteristics of the drive.
Finally go to device manager, and remove or uninstall the device, reboot the computer and setup again. This can sometimes remedy the problem.
ensure that the drive is set as Master/Slave. if on the same Bus/IDE channel as a hard-drive. set as master/slave opposite to what the hard-drive is setup as.
Hope this helps.
Mike @ Compurepair.