Hello, Now you can try the command: man fsl It explains quite well what you should do. The most used option is: 'to add a line containing . /etc/fsl/4.1/fsl.sh to the .bashrc file in a users home directory' or to /etc/bash.bashrc After doing this open a new terminal and it should work. Best, Alexandre Manhães Savio <[log in to unmask]> On 2 June 2011 12:35, Josselin Houenou <[log in to unmask]> wrote: > By, the way, I can now launch the FSL GUI but I can't launch the commands > in the terminal. > The answer to "echo $FSLDIR" is empty. > How can I do ? > Thanks, > Josselin >