Solved.
http://www.cyberciti.biz/faq/linux-create-a-bootable-usb-pen/
showed me the principles.
-----Original message-----
> From:Bill Maidment <[log in to unmask]>
> Sent: Tuesday 8th July 2014 21:40
> To: [log in to unmask]
> Subject: SL7 Alpha USB install issue
>
> I created a USB install drive (16GB) using:
> livecd-iso-to-disk --format --reset-mbr SL-7-x86_64-DVD.iso /dev/sdd
> It boots OK, But it only does a network install. What am I doing wrong?
>
> Regards
> Bill Maidment
>
>