For mag250 use folder mag250, for mag322 ceate folder named mag322 etc...
create a directory on usb called mag250 and copy the bootstrap for mag250 and the imageupdate 

<<TAKE CARE OF: the folder must be named mag250, the bootstrap must be named to bootstrap and the imageupdate must be named imageupdate and all copied to the folder mag250>>
go into the bios of the mag using next:
-Power off STB MAG200/250.
-Press and hold the «menu» on the remote (or the power button on the front panel). Menu button on new remote
Without releasing the «menu» (or the power button on the front panel) Power on STB MAG200/250.

UPGRADE PROCEDURE:
In the boot menu (BIOS)

On a USB drive should be two files imageupdate and bootstrap

Enter The BIOS
Select â€oUpgrade Toolsâ€?, pressing enter on the remote control to the right
Select â€oUSB Bootstrapâ€?
Connect the USB flash drive and click OK to confirm the beginning of the update process
Wait for the update, STB will reboot.
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