Integrating PHP - Apache in windows

I was trying to intgrate php into apache. My PHP version was PHP 5.1.4 and Apache was Apache 2.0.58 in a Windows XP machine.

I added my php5_apache entry into the httpd.conf of apache
"LoadModule php5_module d:/php/php5apache2.dll"

Then I added
"PHPIniDir d:/php
AddType application/x-httpd-php .php "

In the php.ini file I had uncommented "extension=php_mysql.dll" because I wanted php to use mysql and Apache was simply refusing to load the dll saying "D:\PHP\ext\php_mysql.dll is not found!" So much for legible error messages! Then I was trying to troubleshoot this thingy when I came across this entry which proved to be my savior. I just copied libmysql.dll from d:\php to my system32 folder and Apache stoppped complaining!

But I simple couldnt understand why the dll was not being found!