my key lost. what i need to do now if i want to update my xbox360 to the new xtream ver???

You can read the key off of the firmware currently on your drive. Even it is flashed with an old xtreme version you would still had to have put in your drive key to get it to work.

theres no need for havin 300 odd threds about the same topic use the search button
look here
http://forums.xbox-scene.com/index.php?showtopic=561011

n/m