I'm working on a client site that is hosted on someone's DIY Debian Linux server [Apache/1.3.33 (Debian GNU/Linux)], and I'm trying to install a script that requires PHP5. By default, the server parses .php files with PHP 4.3.10-22, which is configured at /etc/php4/apache/php.ini, according to phpinfo(). On the server I can see a config directory for PHP5 adjacent to the PHP4 directory: /etc/php5.0/apache2/php.ini. I have tried multiple methods to enable PHP5 for the document root where the site's files are hosted, including all available methods mentioned here. By far, the most common suggestion I've found is to add one or both of the following lines to the site's .htaccess file: AddHandler application/x-httpd-php5 .php AddType application/x-httpd-php5 .php Trouble is, when either or both of those lines are present, the site forces my browser to download any .php files requested, without parsing the PHP at all. All of the other methods mentioned in the above article cause a 500 Internal Server Error. There is no hosting control panel I can access in a browser to enable PHP5 for the site, but I do have shell access. When I asked the server administrator about this issue, he encouraged me to search for the answer on Google. Where could I begin to troubleshoot this issue? Are there ways to test or verify the server's specific PHP5 installation and configuration, using the command line or some other method? Do you have other suggestions to enable PHP5?