Make sure you generate the locales\\
<code>
>locale-gen en_US.UTF-8
>dpkg-reconfigure locales
</code>

Then update the locale via
<code>
update-locale LANG=en_US.UTF-8
</code>
You may have to do LANGUAGE and LC_ALL too..

Try editing the ''/etc/environment'' to\\
<code>
LANGUAGE=en_US.UTF-8
LC_ALL=en_US.UTF-8
LANG=en_US.UTF-8
LC_TYPE=en_US.UTF-8
</code>