PHP start up cannot find the extensions

I have installed PHP 5.0.2 from the installer off of php.net running on Windows XP Pro with the IIS server stuff installed. I know that it didn't come with the external extensions so I downloaded the full zip file and copied the dlls into the following directory: C:\PHP\ext Then I opened php.ini in C:\Windows and changed the extension_dir command to extension_dir="C:\PHP\ext" Then I uncommented out the php_mysql dll in the list of extensions. Despite having done all of this I still cannot get php startup to load my extension. I get the error: PHP Warning: PHP Startup: Unable to load dynamic library 'C:\PHP\extensions\php_mysql.dll' - The specified module could not be found. in Unknown on line 0 I can browse right to php_mysql.dll using the exact path that it gives me in the error message. Any ideas what is wrong? thanks, Danny