Things You'll Need
Instructions
Connect both the HDD and memory unit or USB flash drive to your Xbox 360.
Power on the console.
Go to the Xbox 360's dashboard menu.
Go to "My Xbox," scroll to "System Settings" and press "A."
Highlight "Memory" then press "A."
Choose the USB flash drive or memory unit from the resulting storage selection list by highlighting it and pressing "A."
Find and select the data you want to transfer to the HDD. A menu will appear.
Choose to either "Move" or "Copy" the data. Moving the data moves it off the memory unit or USB flash drive while copying it moves the data to both storage devices.
Select the "HDD" from the storage selection menu to finish transferring the data.