First and foremost. Did you shut down your computer and restart? Second Did you do it manually? Like not with the installer program? I just set up 24 servers with PHP, MySQL,and of course APACHE! I went in manually and did it. Alain has a point with the php.ini file but I think you need to look for Extension_dir in the php.ini file and look to make sure you have it pointing to the right place. That would be your biggest problem. Then create the ever famous
<?php
phpinfo();
?>
file and see if that returns anything.. If you get a good feedback make sure your calling the right database. Save your C:\Mysql\data folder and then reinstall mysql if it all doesnt work. Back up everything in that folder. Then lastly check and make sure that at the bottom of your http.conf file in apache has this at the bottom below </virtualhost>
ScriptAlias /php4/ "C:/php4/"
AddType application/x-httpd-php .php
Action application/x-httpd-php "/php4/php.exe"
AddType application/x-httpd-php .php3
ScriptAlias /php/ "c:/php/"
AddType application/x-httpd-php .php
Action application/x-httpd-php "/php/php.exe"
Man if that doesnt work then just turn it off, go get some Wendy's and a Twinkie and restart your computer. Repeat as necessary.
Hope I can help.
Chad