I'm a rookie with LaTeX, I'm using LyX, but I think this is a LaTeX problem.
Im using this LaTeX preamble for reset counter after parts
\usepackage{chngcntr}
\counterwithin*{section}{part}
But it only works with \part and no with \part*... I need to have no-numbered parts. What can I do? I don't find anything on the net and my attempts don't work (counterwith, part*...).

\part*doesn't step thepartcounter. we need more informations about class used. – touhami Oct 04 '15 at 15:19