I done it before but always forget ..
Uzip the downloaded PHP zip file to C:\
Rename the folder to PHP.
Take command prompt and change to C:\PHP directory
Put the below commands.
php.exe -d phar.require_hash=0 PEAR\go-pear.phar
pear install DB
Open php.ini-dist in notepad edit following lines and save it as C:\Windows\php.ini
include_path = “.;c:\php\include;c:\php\pear”
extension_dir = “C:\PHP\ext”
display_errors = Off
MySQL should be installed and running..
create test.php put <? phpinfo(); ?> in it and save it in your default web dir.
restart apache from command line
C:\Apache\bin>httpd.exe -k restart
Search for string “MySQL Support” .Check If it is there and enabled.