php_pdo.dll in PHP 5.6.23

I'm installing Composer on xampp, but it's missing the php_pdo.dll .

In php.ini, the lines are already ok:

extension=php_pdo.dll
extension=php_pdo_mysql.dll
extension=php_pdo_sqlite.dll
...

In the ext folder, contains these files (ref. as extensions):

php_pdo.dll
php_pdo_mysql.dll
php_pdo_sqlite.dll
...

Command php.exe -v :

PHP Warning:  PHP Startup: Unable to load dynamic library 'F:\Xampp\php\ext\php_pdo.dll' - NÒo foi possÝvel encontrar o m¾dulo especificado.
 in Unknown on line 0

  

I've tried:

     

I downloaded xampp portable, and it really does not have this dll in the ext folder.   In a quick search, I could not find the file to download.

     

I downloaded the dll of a site, version 5.1.2.2, and it is failing.

Does anyone have any idea why this dll does not come and how to fix or where to download?