I get "MySQL Support is off" when trying to install on Vista (localhost)

ZenCart version: zen-cart-v1.3.8a-full-fileset-12112007

I'm trying to go through the process of installing zen cart on my vista laptop and everytime I go to the localhost/zencart/zc_install/index.php the file blows up with:

MySQL Support = OFF

I checked the php.ini and uncommented out the following:

extension=php_gd2.dll
extension=mysql.so

I restart apache and still get the MySQL Support = OFF.

If I uncomment extension=php_msql.dll then the zencart crashes apache.

Webserver = Apache/2.2.11 (Win32) PHP/5.2.9-2
HTTP Host = localhost
Path_Translated = C:/Apache/wwwroot/zencart/zc_install/index.php(SCRIPT_FILENAME)
Real Path = C:\Apache\wwwroot\zencart
PHP O/S = WINNT
PHP API Mode = apache2handler
PHP Max Execution Time per page = 30

I even create a database in mysql called zencart.

Any suggestions?

When ever I go to:
http://localhost/zencart/zc_install/index.php?main_page=license

I have read and agree to abide by the Terms and Conditions as stated above.

click continue

i get a crash:

Apache HTTP Server stopped working and was closed
A problem caused the application to stop working correctly. Windows will notify you if a solution is available.

First off create a php script called phpinfo.php and in the script write the following,

<?php phpinfo(); ?>

Place it in your web root and call it from web browser,

http://localhost/phpinfo.php
that should show u what php extentions are installed and all paths, also it would help to know what version of windows you are running. i runn server 2003 and run my site on php as a fast cgi under iis with out apachee. also make sure that mysql instance is running and permissions r set properly. some times it helps to install phpmyadmin under a differnt site folder and call that local host for access to you MySql database

Hope this helped