I am trying to upgrade my x360 with the retail 120gb seagate hd that is compatible using software to flash the firmware so the x360 recognizes and you can use it. It says to put a copy of dos onto a thumb drive, disconnect your computers HD, and boot to dos to flash the firmware of your new drive to use it with your 360. do I have to make the thumbdrive bootable, and install dos directly to it, then restart? or should I make a bootable floppy and try it? Any suggestions would be appreciated. Thanks