Back again. The best and easier (in my humble opinion) way to create a bootable flash drive is to use UNetbootin.
That should fix you right up.
+1 for Unetbootin.
I've always had more luck creating bootable USB sticks with Unetbootin than any other method (except good old dd for iso's that support it).
I have been using it for a while. Only one failure (Debian) and I am sure that was my fault. Never had a problem with any Ubuntu or Lubuntu ISO. It is so easy.I've always had more luck creating bootable USB sticks with Unetbootin than any other method
It seems It comes from the computer. The USB Live has no error and the MD5SUM is the same.
Nevertheless I keep the command-line and If I enter startx I get : fatal server error : no screens founds