Supuestamente SQL Lite en PHP 5.x en adelante no requiere nada más que habilites dicha extensión en tu php.ini. La "librería" en sí está incorporada como parte de esa librería/cuerpo de PHP .. (no es como Mysql por ejemplo que requiere de otras .dll por médio que son las "librerías" en sí .. no la "extensión" que son las "funciones" que se añaden a PHP para manejar ese tema concreto).
Consejos ..
1) No habilites más extensiones de las que requieras y hazlo una a una .. Puede que el problema te lo esté dando otra extensión -que sí- que requiera alguna otra .dll extra.
2) Fijate en los comentarios de los usuarios de la extensión en concreto que tengas que instalar ..suelen haber comentarios interesantes con soluciones.
http://www.php.net/manual/en/ref.sqlite.php
No especificas que versión exacta de PHP usas .. pero es necesario que veas la documentación oficial .. por qué hay "detalles" sobre PHP 5.0.x y 5.1.x ..
Cita: Installation
Read the INSTALL file, which comes with the package. Or just use the PEAR installer with pear install sqlite. SQLite itself is already included, You do not need to install any additional software.
Windows users may download the DLL version of the SQLite extension here: (php_sqlite.dll).
In PHP 5, the SQLite extension and the engine itself are bundled and compiled by default. However, since PHP 5.1.0 you need to manually activate the extension in php.ini (because it is now bundled as shared). Moreover, since PHP 5.1.0 SQLite depends on PDO it must be enabled too, by adding the following lines to php.ini (in order):
extension=php_pdo.dll
extension=php_sqlite.dll
On Linux or Unix operating systems, if you build PDO as a shared extension, you must build SQLite as a shared extension using the --with-sqlite=shared configure option.
SQLite 3 is supported through PDO SQLite.
Windows installation for unprivileged accounts: On Windows operating systems, unprivileged accounts don't have the TMP environment variable set by default. This will make sqlite create temporary files in the windows directory, which is not desirable. So, you should set the TMP environment variable for the web server or the user account the web server is running under. If Apache is your web server, you can accomplish this via a SetEnv directive in your httpd.conf file. For example:
SetEnv TMP c:/temp
If you are unable to establish this setting at the server level, you can implement the setting in your script:
putenv('TMP=C:/temp');
The setting must refer to a directory that the web server has permission to create files in and subsequently write to and delete the files it created. Otherwise, you may receive the following error message: malformed database schema - unable to open a temporary database file for storing temporary tables
Un saludo,