Hello, please help me.

I've well installed fox contact few weeks ago, but i had some problem with me joomla, so i need to reinstall it again. But i have an error message when i try to do it : Composant : erreur à l'installation

And the module is well installed but isn't shown in the list.

Have you an idea of my problem ?

Thanks for your help.
Simon

I suppose you edited some files and then uploaded using FTP and something is gone wrong with file permissions.
No problem until you decide to reinstall or upgrade the component, but when you decide to reinstall, and if the reinstallation fails, Joomla will WIPE OUT the extension's directories without a warning (they consider this behaviour a "roll back" of a failed installation).
All subsequent installations will fail with "Installation error".

You should resolve in this way:

1) Delete from the server the following files and directory if they still exist:

• directory administrator/components/com_foxcontact/ and all its content
• files administrator/language/yy-YY/yy-YY.com_foxcontact*
• directory components/com_foxcontact/ and all its content
• files language/yy-YY/yy-YY.com_foxcontact.ini
• directory media/com_foxcontact/ and all its content

2) Open your database, go to the table jos_extensions and find all rows related to com_foxcontact.
You can detect these rows with this query
SELECT * FROM `jos_extensions` WHERE element LIKE '%fox%';
Delete these rows from the database table.

3) Do similar steps for the module.

4) Now you are good to go with a fresh install.

First, thanks for your response.

I've checked all as you describe, but i still can't install the component. The module is well installed.

I have no idea.

Please try running the Removal Tool and tell me if it works.