Install MySQL with php 5.2.12

[Albert Trippenzee]

Hi i installed windows 2008 (win32) and php 5.2.12 on a server and installed mysql-essential-5.1.42-win32.

But when i tryed to install Joomla i get the message that there is no MySQL Support.
When i trying to open phpmyadmin i get the message: Cannot load mysql extension. Please check your PHP configuration. - Documentation

But when i look at the server and start the MySQL administration than i see that MySQL is running.

I looked on the web and looked and find out that in the PHP.ini i have to Uncomment the following lines by removing the ; so i get:
extension=php_mysqli.dll
extension=php_mbstring.dll
extension=php_mcrypt.dll

But i can not find this on the php.ini.

So what i im doing wrong?