i do this with my xbox 360 (download the game and burn it)
big difference on how it works... i have to hack the firmware on the 360 to allow it to play the games.
i use img burn also. along with some other programs for use with higher quality games.
oh. and heres some useful info so i dont just come in here and burn worthless info.
you can burn a dreamcast emulator and all of the DC roms. then play it on your computer.
very simple to do. heres a link to the download.
http://thepiratebay.org/torrent/3520...mCast_Emulator[Chankast]
heres the boot disk for what you are trying to do. i think?
http://thepiratebay.org/torrent/4700...cast_boot_disc
if you download the emulator just find some dreamcast emulator games and have fun!
also if you want to step it up you can download the ps2 emulator.