Then I used a Dam Small Linux to change the Operating system, by booting from an USB pen created by following the instructions on this site:
Iv'e copied the files generated for local disk installation:
to a directory called install on the Dam small linux USB pen.
I've booted the USB pen on the Thinclient, then I've mounted the usb pen:
mount /dev/sda1 /mnt/sda1
I got into error:
"syslinux: possibly unsafe /tmp permissions"
So I needed to correct the permissions of the /tmp directory:
Repeating the process worked great, the system now boots and connects as desired.