Wait, why do you want to burn it? Did you want to play it on a physical Dreamcast or on Chankast? If you wanted to play it on a Dreamcast then the virtual drive is pointless. To burn with Alcohol 120%, choose Burn Image (or something like that), and then a box will show up with all these choices. Choose RAW DAO (RAW Disc-at-once) from a drop down box and set the burn speed to under 24x (this is to ensure good burning, you can try at top speed but sometimes that screws it up).