How do I install php in my laptop

Go to PHP web site (http://www.php.net).
Download PHP (http://www.php.net/downloads.php) for your operating system, compiling or executing installer as necessary.
Follow tutorial (http://us.php.net/tut.php) and installation instructions (http://us.php.net/manual/en/install.php) for your operating system.


What's the problem?

This might help: http://robert-lerner.com/server.php

Shows how to install PHP and MySQL on Windows using Abyss Web Server.

This might not help you if you're only interested in the CLI, but most people use it for its CGI (web) abilities.