HELP!-Laptop refuses to recognise the DVD_RW drive?

I have a Fujitsu Siemens laptop running Vista Home Premium. The built-in DVD_RW (model ND-6750A) is no longer being recognised by the computer and isn't being listed as a recognised (E) drive in My Computer. If I insert a DVD the drive spins up properly, but nothing happens. I know the drive itself is not faulty because it works fine if it is put in an identical laptop.
The Bios still lists the DVD_RW as item 3 in the boot priority order, so what can I do to get the computer to read the DVD again.
ps. My two teenage grandchildren were using the laptop during the holidays so it's possible they've been fiddling with menus and settings.
Your help would be appreciated