HR4420 - Change rights for flash files

Dear all,
I received two HR4420 and tried to update them. For one I succeed but for the other one I could not replace some files because by default some files of the flash were protected (only execute and read access rights). I am unable to change the rights to add also write access right. Can anyone help me ? I am connected via Hyperterminal (xModem) or via FTP client.
Many thanks for your help

Hi Carlos,
I would not normally expect system files to have non-default permissions.
As these routers are new to you, the first thing I would recommend you do is re-flash them using flash writer to install the firmware version that you require.
This will bypass any file permissions and also factory reset the router so you can be sure you have a known good file system and config.

Flashwriter can be downloaded from this page:

Usage instructions are here:

Firmware is available from here:

Make sure you load on the correct firmware for either the Novatel or Option WAN module. If unsure what firmware to install, I’ll need to see the output from the CLI command ‘ati5’.

Hi Ben,
Many Thanks for your answer, I have just seen it. I will try to re-flash it.
Kind regards,