Toshiba SD-R2212 DVD-Rom/CD-RW Combo drive does not read DVD

HP Pavillion ze1230 note book with the above DVD/CD-RW combo drive cannot play any DVD. manufactured CD, CD-R and CD-RW files can be read and written to with no problems. Manufactured DVD, DVD-R, DVD-RW disks will not play in any software applications (windows media player, power DVD or inter-Video). The computer cannot display any files listed on any of the disks in the windows explorer as well. any ideas or drivers that can resolve this?