How does a computer dvd rw show up on the device list , but the maker not have the device.?

Answer 1

*IF* you're saying (for example) The Device Manager shows a, say SONY DVD-RW< but SONY has no listing for it....

It COULD be that SONY makes that particular drive exclusively for your computer's manufacturer. So, you'd have to get any updates, drivers, Firmware, etc from your computer's manufacturer's web site