thank you
(edit: I forgot to add that it's free)
Hope this helps you.
You can edit PHP files with notepad. You do, however, need an active PHP server to process the files. There's plenty of free hosting sites out there with PHP support, or if you prefer, use something like XAMPP to install it on your local machine.
You have to tell the.php files to be opened with Notepad; by right clicking the file, and clicking: "Open with" then just find "Notepad".
Also, I find it easier to find cheap/free hosting which supports FTP and would run the required PHP and MySQL (If you are practicing it also) version and using that. The domain would cost only $10 unless the site allows subdomains.