Do understand that for the PHP codespec to deliver an Email anywhere, in addition to a Webserver you have to have a Mail server running on your computer as well.
Please do a search in Google for an - XP or Vista or Windows 7 - based Mail server. There are several available for download, some are free and some you may have to pay for.
BTW, normally anything on Microsoft Windows you have to pay for, why not consider switching to Linux which come with a built-in Web server and Mail server for free.
Once you've, downloaded and installed the Mail server on your Windows OS, you have to then inform PHP that such a service exists on your Windows box.
This is done by passing appropriate values against PHP directives in the php.ini file.
BTW, if you do not have any mail server installed and running on your local Windows box, you could consider sending all your Emails via a Yahoo or Google email account.
If you are using a Yahoo or Google Email account to dispatch your Emails using a PHP code block, then appropriate Yahoo or Google information such as (Email) Login ID and Password information need to be added to directives in the PHP.ini file.
Hopefully one of these approaches will get you sending Emails successfully via PHP code spec.