Mehdi, I'm going to make one more attempt at trying to resolve your issue. The problem is that I need information in order to diagnose the problem, and I need ALL of the things I listed as bullet points, along with any other information you can provide. The MORE information you can give, the easier it will be to diagnose your issue.
Now... You state that you have two directories where Apache is installed. The new instance of Apache is located in
/usr/local/apache2 if I understand things correctly. This directory is called your
ServerRoot.
What you need to do is the following:
* Check your
/etc/sysconfig/httpd and make sure that the OPTIONS variable has a
-d option that points to your serverroot. Look further up in my thread for how to do this.
* MAKE SURE that the serverroot contains either a directory, or a symlink to a directory, containing the required modules, specifically the PHP5 module. This is EXACTLY why I asked you to supply the error message, so that I can verify if this is true or not.
*
If this does not resolve your issue, I kindly ask you to provide the information I listed in the bulletpoints in my post above. Please list ALL of said information, or I will refrain from assisting further due to lack of relevant information to diagnose your issue.
One more thing. Is there a specific requirement for having two separate instances of Apache? Specifically, did you try
yum install php to enable PHP-support for your existing Apache install?
Please see
Install PHP 5 in Red Hat Enterprise Linux 5 for a guide as for how to install PHP5 support on Red Hat Enterprise Linux 5.