note 15474 added to install-windows

If you're having problems to load an extension module with win32 platform, try changing the extension_dir parameter in php.ini (c:\windows or c:\WINNT) to the absolute path with DOS names. I had c:\Php\extensions and it didn't work, but I've changed to c:\Php\extens~1 and it worked. E.g: extensions_dir = c:\Php\extens~1 extension=php_oci8.dll http://www.php.net/manual/en/install-windows.php