Windows 7 DVD drives vanish from computer, management and yellow exclamation marks in Device Manager

[AZ Road Runner]

I have just done a fresh install and after getting a few programs installed my DVD drives stopped working. They are in the bios and I have tried to update drivers ( claims I have latest ) looked in the registry and I do not have any numbers to edit as has been discribed else ware. I have changed the preferences so that the DVD shows even when empty. Does anyone out there have any ideas?
Thanks