This is how I made the php_mssql extension work on my Windows-Apache-PHP-MSSQL Server.
Download Apache. (I used the Win32 Binary including OpenSSL 0.9.8m (MSI Installer))
Download PHP. (I used the PHP 5.2.13 zip package)
Run the apache installer, select custom install and change the install path the ‘C:\Apache2.2′
Extract the php zip file to ‘C:\PHP’
Open C:\PHP and copy php.ini-recomended to php.ini
Open php.ini and edit the following lines:
Set extension_dir = “C:\PHP\ext”
Uncomment php_mssql.dll
Set error_log = “C:/Apache2.2/logs/phperr.log”
Open C:\Apache2.2\conf\httpd.conf and edit the following lines:
Set DirectoryIndex index.php
LoadModule php5_module C:/PHP/php5apache2_2.dll
AddType application/x-httpd-php .php
PHPIniDir “C:/PHP”
Add “C:\PHP” to the PATH Environment variable
Replace the file C:\PHP\ntwdblib.dll with the copy you just downloaded (v2000.80.194.0)
Restart the Apache service
You can now use all the mssql functions in your php code without errors