Hi palamon, welcome to BC.
the hardware is ok, cdrom does see a cd
I assume this is a combo drive?
If it is, a hardware problem (defective drive) cannot be ruled out yet. It is possible for a defective drive to read a cd but not a dvd disk. When you insert a dvd disk, open my computer or windows explorer to see if the drive shows a disk inserted.
If it does, try this little player.
There is no installer for it. You just run the .exe and the player will launch. With the dvd inserted, click the play arrow. Let us know what happens. Also post your version of windows and the player you normally use please.