hello manowar30, i think you can better achieve this by using the mozilla.cfg file in the programs folder. for reference refer to http://kb.mozillazine.org/Locking_preferences

hi manowar30, you mean that the editing user.js file does not saved in the profile folder?

Editing user.js entries

thank you

No, i already have an user.js in my profile. now i install the new version of firefox but the new user.js do not overwirte the old one in the profile...

i ve copied it to ../firefox/defaults/profile

from there it should be copied in the profile but it do not overwrite the old one in the profile...

I thing you must try madperson's reply (the locking preferences)

thanks again

You can use these functions in mozilla.cfg:

defaultPref();  // set new default value
pref();         // set pref, but allow changes in current session (prevails user.js)
lockPref();     // lock pref, disallow any changes

You need to create a batch file.. to copy the user.js file into the profile directory. The problem is... 1st The directory generates a random name when installed. 2nd it places a . in the directory name it creates. copy will not work.

To get around this .. there is a simple "for" command you can place in a batch file and will do the trick. example shown below.

set folder=%APPDATA%\mozilla\Firefox\Profiles

for /f %%i in ( ' dir /a:d/b "%folder%" ' ) do if exist "%folder%\%%i\." copy /y "C:\pathtofile\user.js" "%folder%\%%i\">nul