do you want to back up an original or play a backup?
To backup an original you have to rip it to your xbox using your preferred game manager, then ftp it to your pc and run Xiso to convert to an iso then burn it to a dvd.
To play a backup use Xiso to extract the game and ftp to the games folder (usually in F drive if large hard drive)
to back up an original game u want craxion or qwix-an active ftp connection to ur xbox from ur pc
1 pop game in xbox -(make sure u aint got autolaunch selected)
2 open craxion/qwix on pc
3 select rip from disc
4 make a cuppa and wait
to copy a copy just use alcohol either make disc image or disc to disc
if u have an iso on ur pc again use qwix load is into this then chose ftp upload all to e;/games or f:/games if u have bigger hd
also u could open ftp connection-look in d on xbox this will b ur game disc and ftp straight to ur pc then use qwix to create an iso from all the files-if u need more help pm or msn me
check xbins on irc for any files you need or try here