Stephen Harris a écrit :
But did you uninstall Cygwin? Cygwin comes with a different version of sh.exe and sed.exe than Minsys. So if you put Minsys ahead of Cygwin in windows Path, then LyX will read that directory before Cygwin. That means it will use the Msys versions of sh.exe and sed.exe which are the correct versions of those files needed to install LyX. Uninstalling Cygwin's LyX does not uninstall Cygwin's sh.exe and sed.exe
Thank you Stephen for your help. I did what you suggested and I put Minsys ahead of Cygwin in windows Path. However the problem always existed. I read that one can solve the problem if one makes "Sh configure" in the Ressources folder of LyX and now it goes well :-)
--radwan. -- Radwan JALAM AGROCAMPUS RENNES 65, rue Saint Brieuc 35042 Rennes cedex - FRANCE http://www.agrocampus-rennes.fr/math/jalam