Windows Server under IIS6/7 PHP can not load php_curl.dll, such as dynamic link library _win server

Problem:
PHP cannot load the Php_curl.dll dynamic link library in IIS6 or IIS7.
Workaround:
In the PHP manual has the relevant description: Php_curl.dll;curl, client URL library function library; required: Libeay32.dll,ssleay32.dll (Shipped)
So just copy the two libraries of Libeay32.dll,ssleay32.dll to the%windows% directory.

PS: There are many people on the Internet to copy the above two libraries to%system32%, and this completely does not work, the article will only copy, and without textual research, is simply fraught, wasting people's time.

After my next study, I found a rule that PHP cannot load the general solution of an extension library under Windows. The steps are as follows:
1, check the PHP extension folder (such as:/php/ext/) to expand the library's related dynamic link library.
2, in the PHP manual to find the extension can not be loaded instructions.
For example, the library that cannot be loaded is php_openssl.dll, and the instructions found in the PHP manual are: php_openssl.dll;openssl function library; required: Libeay32.dll (shipped). This shows that loading the Php_openssl.dll library also requires a Libeay32.dll library.
3, copy the Libeay32.dll library to the%windows% directory. Restart IIS, you can see the OpenSSL in the phpinfo.php. It should be noted that such PHP as Libeay32.dll (already shipped with) is copied to the%windows% directory.