I also have a CD/DVDRW on my desktop, but it can recognize the DVD which I insert.

But if you want to copy the DVD, you will need a DVD Copy software. You have several options in fact.

Copy DVD to blank DVD disc: since CD/DVDRW doesn't have burning function, you still need a DVD drive with burning function (that seems to be DVD-RAW), and you need a DVD Copy software as well. Download DVD Copy here and read the Copy DVD Guide , I'm sure you'll get it coz the operation is quite easy.

Copy DVD to ISO(image file) or DVD folder saved on your computer: to do that, a CD drive may be enough, but if you also want to watch it on your computer, you still need a DVD drive.

wish it helps!