Install ZendOptimizer on Windows Plesk

Download the ZendOptimizer from http://www.zend.com/en/products/guard/downloads
Download Link – http://downloads.zend.com/optimizer/3.3.3/ZendOptimizer-3.3.3-Windows-i386.zip

Extract the zip file and copy file ZendExtensionManager.dll and folder Optimizer-3.3.3 to C:\Program Files (x86)\Parallels\Plesk\Additional\PleskPHP5\extras\lib

Now open C:\Program Files (x86)\Parallels\Plesk\Additional\PleskPHP5\php.ini and add the below lines at the end of the file.
[plain]
[ZEND]
zend_extension_ts = "C:\Program Files (x86)\Parallels\Plesk\Additional\PleskPHP5\extras\lib\ZendExtensionManager.dll"
zend_extension_manager.optimizer_ts="C:\Program Files (x86)\Parallels\Plesk\Additional\PleskPHP5\extras\lib\Optimizer-3.3.3"
[/plain]
Now save the file and restart the IIS and it’s done.
[bash]
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.

C:\Users\servertechsupport> iisreset /restart
[/bash]

You can create a phpinfo file with below contents to confirm that zendoptimizer is loaded.
[php]
<?php
phpinfo();
?>
[/php]