Getting Error on Step 5 (Database Setup) of install

The error I'm reciving is "You must have the MySQL PHP module installed "
I have install PHP5 and MySQL 4.1. I have also added the path to the PHP directory.
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The following information is required to get an answer:
Get this information from the PHP diagnostic (in the configuration wizard).
Gallery URL (optional but very useful):
Gallery version: 2.0
Apache version: using IIS 5.1 for windows not apache
PHP version (don't just say PHP 4, please): php-5.0.4
Graphics Toolkit: ?
Operating system: windows XP pro
Web browser/version (if applicable): explorer 6.0