Why does my Android device create a CD-ROM device on my computer? When connecting my Android phone (HTC One V) to my PC via USB (in HDD mode), it creates two removable devices for the internal memory and the sd card - as it should.

However, it also creates a CD-ROM device which is always in the "no media inserted" status. Why does it create one and does it have some purpose?
Some network-branded devices use a virtual cd-rom device to supply their own tethering software. If your phone's tethering isn't restricted and the device created is empty, I'd say it's safe to ignore it.