where to put php.ini exactly ?

You will have to contact your web provider, some don't allow you to change values in php.ini

For .htaccess you can try this:

Code:

php_value memory_limit 128M
php_value post_max_size 200M
php_value upload_max_filesize 200M

Hello InsiteFX, and thx for your answer

I have asked my ISP and he ensured me I could change that in a new php.ini file

on local (easyphp) your changes work fine(!!) on the prod server they crash (error 500) and
on local, the php.ini doesn't work, but returns no error, on prod serv it gives the error in my above post