PHP / cURL on Windows install: "The specified module could not be found."

A tip is to use the WAMP-installer. Everything just works. It's not IIS though - so if it is important - you should ignore my advice. ;)

EDIT: I saw that you found the solution so I voted it up. +1

libeay32.dll and ssleay32.dll have to be path-accessible for php_curl.dll to work correctly.

In Control Panel -> Search -> Advanced System Settings and use the button Environment Variables.

Under System Variables find Path add the c:/php folder (or whatever path) and restart Apache.

Problem solved!

Although the error message said The specified module could not be found, this is a little misleading -- it's not that it couldn't find php_curl.dll, but rather it couldn't find a module that php_curl.dll required. The 2 DLLs it requires are libeay32.dll and SSLeay32.dll.

So, you have to put those 2 DLLs somewhere in your PATH (e.g., C:\Windows\system32). That's all there is to it.

However, even that did not work for me initially. So I downloaded the Windows zip of the latest version of PHP, which includes all the necessary DLLs. I didn't reinstall PHP, I just copied all of the DLLs in the "ext" folder to my PHP extensions folder (as specified in the extension_dir variable in php.ini), and I copied the versions of libeay32.dll and SSLeay32.dll from the PHP download into my System32 directory.

I also did an iisreset, but I don't know if that was necessary.