To use PDO, check whether PDO extension exist or not. Try to open your php extension folder. For example, in my computer, the directory: app/php5/ext.

Then, open your php.ini. Usually within c:/windows (depend on your php installation). Uncomment at line extension=php_pdo.dll, extension=php_pdo_mysql.dll. If still not exist, write them.

Restart your apache. You can restart from services. If, you use windows XP, you can access from start > control panel > Performance and Maintenance > Administrative Tools > Services. Find apache, then click restart.

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