This articles provides information on using a custom PHP.ini file on your PHP based site hosted on 3Essentials Windows hosting plans.  For information on this topic for Linux hosting plans, please see Using a custom php.ini - PHP on Linux.

• To determine your Plesk version, go to your control panel, and look at the version noted on the login page.
• To determine your PHP version and mode, log into your control panel, click your domain, click SETUP, and look for the PHP option.  Note the version selected.  If ISAPI is not checked, then you are running in PHP as CGI mode.
  • you can change the PHP version and mode (CGI or ISAPI) to meet your needs (note the impact to custom php.ini options listed below) 

• Plesk 7.5.6
  • PHP 4 as an isapi extension: NO custom php.ini supported.
    • The server's (global) php.ini is used which has standard set of values which are not changeable in a shared hosting environment.
    • PHP 5.x not available on Plesk 7.5.6.
  • PHP 4 as CGI : YES.  custom php.ini supported.
    • To use your own custom php.ini, simply upload it to your httpdocs folder.
    • PHP 5.x not available on Plesk 7.5.6.
• Plesk 8.2 and 8.6
  
  • custom php.ini support listed by version/mode of php:
    • php4 cgi: YES*
    • php4 isapi: NO
    • php4 fastcgi: php4-fastcgi mode is not supported by 3Essentials, despite being available in the plesk control panel. Please choose php4-cgi mode instead.
    • php5 cgi: YES**
    • php5 isapi: NO
    • php5 fastcgi: php5-fastcgi mode is not supported by 3Essentials, despite being available in the plesk control panel. Please choose php5-cgi mode instead.
  • *PHP 4: 3Essentials places a sample php.ini file for PHP4 in your httpdocs directory when your domain is originally created.  It's called php.ini.  Domains are set up by default to use PHP 4, so this php.ini is there, ready to go, for your PHP 4 execution.  Modify this file as you need - It is IMPORTANT to use this sample file, as it includes necessary values for PEAR, which provide SMTP-AUTH MAIL functions not natively supported in PHP***.
  • **PHP5: SWsoft (the makers of the Plesk control panel) added support for PHP5 to Plesk 8.x, however they did not configure it such that it supports a custom php.ini file, however 3Essentials has implemented a workaround for customers which enables you to have use a php.ini file... if you wish to use php5 on your Plesk 8.2 hosted domain, you must follow these steps:
    • You must submit a support request asking us to add the php5 script mappings for you. If you do not do this, you'll get "page not found" when trying to access a php file via your site, if you've selected php5.  If you switch back to php4, you must submit a support request for us to remove the php5 script mappings.
    • You must use a php.ini in your httpdocs directory.  3Essentials places a sample php.ini file (for php4) in your httpdocs directory when your domain is originally created.  We also place a php5 sample as well, it's called php5sample.ini.  If you chose to enable php5, you need to RENAME the php5sample.ini to php.ini in your httpdocs folder.  Modify this file as you need.  It is IMPORTANT to use this sample file, as it includes necessary values for PEAR, which provide SMTP-AUTH MAIL functions not natively supported in PHP***.  
• Plesk 9.x
  • custom php.ini support listed by version/mode of php:
    • php4 cgi: YES*
    • php4 ISAPI: NO
    • php4 fastcgi: NO
    • php5 cgi: YES*
    • php5 ISAPI: NO
    • php5 fastcgi: NO
  • * Note that the php.ini file must ACTUALLY be named php-cgi-fcgi.ini.  

***For more information about the PEAR Mail functions for SMTP-AUTH MAIL support, please see article 394: http://knowledge.3essentials.com/web-hosting/article/394/Sending-mail-with-PHP-using-SMTP-auth.html