setting up gdm
/usr/bin/gdm : error while loading shared librairies : libpng12.so.0 : cannot open shared objet file : no such file or directory
ERROR : could not start the display Manager
gdm : no process killed

ensuite en tapant ==> startx

xauth : error while loading shared librairies : LibX11.so.6 : cannot open shared objet file : no such file or directory