参考官方解决方法：http://nz.php.net/manual/en/curl.installation.php

1、php安装目录下的ext文件夹下面是否有php_curl.dll文件，然后右键->属性->详细信息，查看版本号是否和PHP版本一致；
2、php.ini文件;extension=php_curl.dll前面的";"去掉
如果以上方法还不行的话，请继续往下；
3、（如果是windows32位系统）复制 php_curl.dll, ssleay32.dll, libeay32.dll 到system32目录下
4、复制 libssh2.dll 到 Apache24\bin 目录下，然后重启服务

Note: Note to Win32 Users
In order to enable this module on a Windows environment, libeay32.dll and ssleay32.dll must be present in your PATH. You don‘t need libcurl.dll from the cURL site.

I had to also also copy libssh2.dll into my Apache24 folder for this to work with my PHP 5.6.2 installation. So altogether I had to do the following:

Move to Windows\system32 folder:
libssh2.dll, php_curl.dll, ssleay32.dll, libeay32.dll

Move to Apache24\bin folder
libssh2.dll

Uncomment extension=php_curl.dll

windows下PHP中Fatal error Call to undefined function curl_init()的解决方法