I have a Dell XPS Dimension desktop which came with a DVD writer,
Philips DVD+ RW DVD8631 ATA Device. I installed Vista Ultimate on this
machine. Similar to your situation the drive was visible in the Device
Manager but not in My Computer. I could not physically open the drive by
pressing the button in front, nor would its LED light up during booting.
I went into the BIOS setup to see whether it was visible there. It was
visible as a PATA drive and the status was ON. Just on a whim, I turned
it OFF and rebooted. To my utter astonishment the drive was visible now
in both Device Manager as well as My Computer! The drive appeared to be
I went back into the BIOS and turned the drive back ON. It remained
still visible in My Compuetr and functional. I do not understand the
rationale of this behaviour but hope that it works for you too.
When I checked the driver it appears to be a generic one that comes
with Windows (cdrom.sys).