Here is the steps to enable curl on Windows :
...
; Directory in which the loadable extensions (modules) reside.
; http://php.net/extension-dir
; extension_dir = "./"
; On windows:
extension_dir = "C:\PathToMyPhp\ext"
...
extension=php_curl.dll
...
[curl]
; A default value for the CURLOPT_CAINFO option. This is required to be an
; absolute path.
curl.cainfo = C:\PathToMyFile\cacert.pem
1 - Make sure your extension_dir point to the php extension directory.
2 - uncomment or add the extension .dll name .
Here is the right syntax by convention for php extensions : php_nameOfTheExtension.dll
The .dll are placed in the extension directory of php or you must place it here in case of 3rd party download.
3 - cacert.pem is optional and is used for SSL transactions.
Download here : https://curl.haxx.se/docs/caextract.html
4 - Check with phpinfo() if curl is in the list and check the configuration.
5 - In case of error, check the error.log and access.log of Apache
Edit 1 :
6 - I forgot : add the paths of your php directory to the Windows Environment PATH Variable for .dll dependencies.
Question/Response here :
Enable CURL on Windows For PHP5.6.4
Edit 2 :
Here is the path for the files :
Depending on MySQL installation & version
C:\Program Files\MySQL\MySQL Server 8.0\bin\libeay32.dll
C:\Program Files\MySQL\MySQL Server 8.0\bin\ssleay32.dll
Depending on your php directory
C:\php7\libssh2.dll
Edit 3 :
Example of extensions configuration with the right syntax taken from PHP5 but working also for PHP7 :
; Windows Extensions
; Note that ODBC support is built in, so no dll is needed for it.
; Note that many DLL files are located in the extensions/ (PHP 4) ext/ (PHP 5+)
; extension folders as well as the separate PECL DLL download (PHP 5+).
; Be sure to appropriately set the extension_dir directive.
;
;extension=php_bz2.dll
extension=php_curl.dll
extension=php_fileinfo.dll
;extension=php_ftp.dll
extension=php_gd2.dll
;extension=php_gettext.dll
;extension=php_gmp.dll
extension=php_intl.dll
;extension=php_imap.dll
;extension=php_interbase.dll
;extension=php_ldap.dll
extension=php_mbstring.dll
extension=php_exif.dll ; Must be after mbstring as it depends on it
extension=php_mysqli.dll
;extension=php_oci8_12c.dll ; Use with Oracle Database 12c Instant Client
;extension=php_odbc.dll
extension=php_openssl.dll
;extension=php_pdo_firebird.dll
extension=php_pdo_mysql.dll
;extension=php_pdo_oci.dll
extension=php_pdo_odbc.dll
;extension=php_pdo_pgsql.dll
extension=php_pdo_sqlite.dll
;extension=php_pgsql.dll
;extension=php_shmop.dll
; The MIBS data available in the PHP distribution must be installed.
; See http://www.php.net/manual/en/snmp.installation.php
;extension=php_snmp.dll
;extension=php_soap.dll
extension=php_sockets.dll
extension=php_sqlite3.dll
;extension=php_tidy.dll
;extension=php_xmlrpc.dll
extension=php_xsl.dll
zend_extension="C:\php-7.1.22\ext\php_opcache.dll"
zend_extension="C:\php-7.1.22\ext\php_xdebug-2.6.1-7.1-vc14-x86_64.dll"
Hope this will help.