Plug your USB drive into the console. Navigate to Settings > System Settings > Storage . Select the USB Storage Device and choose Configure Now to format the full 2 TB (or up to your drive's capacity) for Xbox use. Select Your Game: Insert the game disc into the tray.
Select Install . When prompted, choose your USB Storage Device as the destination. Method 2: Manual Transfer (Modded RGH/JTAG Consoles) install games xbox 360 usb best
This is the safest way to use USB storage on an unmodified Xbox 360. Plug your USB drive into the console