You might be conflating "PHP can use opcode caching" and "osTicket uses opcode somehow".. osTicket does not. There is no opcode specific code in the repos. opcode caching is performed at the server level for ALL PHP scripts, that's how it works. (Any text matches in the repo are actually part of the included PEAR DNS packages, and aren't osTicket code).Also, there are quite a few opcode caches now. (In case you didn't know), zend_opcode is commonly referred to as just opcache.dll, however, you have to link it with: "zend_extension=php_opcache.dll" not just extension=. (According to S/O). Make sure you have the correct TS and NTS versions for your version of PHP (read about that here: https://stackoverflow.com/a/7204804) and ensure that the version of the opcache dll is the same as the version of PHP you've installed. Then ensure that you're loading PHP using that php.ini.. not always the case (depends on CGI/ISAPI/FastCGI etc, and on linux, Apache or FPM too).I've just had a look at PHP Manager for IIS (never used it before). Last released in 2011.. I'm sure it's current.. You're saying it's included in 2012R2? I'm not seeing it in my IIS box, the docs say it needs to be installed manually (https://technet.microsoft.com/en-us/library/hh994592(v=ws.11).aspx) and refers to wincache again.. maybe you can't use zend_opcache but should be using wincache? There is a doc for the opcode win_cache on 2008 here: https://docs.microsoft.com/en-us/iis/application-frameworks/install-and-configure-php-on-iis/use-the-windows-cache-extension-for-php Dunno mate, never needed/used a point and click manager for PHP before. It's text-files, just type what you need and save.. According to the phponwindows site: https://www.microsoft.com/web/platform/phponwindows.aspx the latest is PHP 5.3.5.. how current. So, I'm guessing you installed it yourself then. However, if you read the docs here https://technet.microsoft.com/en-us/library/hh994592(v=ws.11).aspx it says: The PHP 5.4 version does not work with the WinCache extension version 1.1. Use PHP 5.3 until this problem is resolved.Lovely.. Good work Microsoft. OK, more than a few seconds of Googling, it's always been so easy for me mate, I forget how bloody complicated and frustrating it is on Windows.