1. Download Xbox 360 April 2010 System Update.
2. Extract it to a root directory of an empty USB flash drive
(FAT32) or burn it onto an optical media device (CD/DVD).3. Turn off the Xbox 360.
4. Remove the hard drive from the Xbox 360 completely.
5. Insert the USB flash
drive/optical media into the Xbox 360 and turn it off again.6. Power up the Xbox 360 and follow the instructions on system update screen.
7. After system update finishes, turn the Xbox 360 on and off at least twice.
8. Turn off the Xbox 360 again.
9. Plug the hard drive back into the Xbox 360.
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