A friend's laptop DVD drive is suddenly no longer detected. It's going to be difficult to walk him through going into the BIOS (he's not local). I wonder if it is even worthwhile i.e. whether the BIOS settings can be corrupted by a virus. Are BIOS settings formatted in a standard way such that a virus writer would know what to alter? FYI, he did reinstall the OS and the drive is still not detected.
There are virusses that can flash your BIOS, but it's very much unlikely that a virus tampered with your BIOS to disable the DVD drive. On top of that, every BIOS is different, so a virus should know how to flash the specific type. A hardware issue is much more likely. It's probably a malfunctioning DVD drive or motherboard.
But I wonder, how did your friend reinstall the OS without a disk drive? If he installed the OS through that drive, it's probably a driver issue.
viruses can flash your BIOS rending it unusable, but it is highly unlikely that it will temper with settings in your BIOS by changing the CMOS RAM configuration since the arrangement is different for different boards.
it is more likely that the DVD drive is broken rather than a uber-strange computer virus disabled it