Xbox 360 Boot Disk V2.4 [work] Now

The use of boot disks is largely considered obsolete due to more advanced modification methods: LT+ 3.0 Firmware:

Check out these guides for modern alternatives like softmodding and SSD upgrades: Xbox 360 boot disk v2.4

Once booted, you are greeted with a blue background and yellow text. This is not pretty, but it is powerful. The use of boot disks is largely considered