I highly recommend
Apache2Triad. It's an apache package which includes Apache, PHP, MySQL, FTP, POP/SMTP server, and lot more.
Once it's installed on your computer there's a file you need to edit called 'default.conf' and change the default directory to be served, for example 'c:\webserver'.
Now you're computer is a webserver, you can test your own websites going to
http://localhost/ or
http://127.0.0.1/
Just be sure to have port 80 redirected to your computer from your router.