This page is to guide people who have done he following steps:

But have the following problem

 

Ok, now this could be due to a few reasons, let's check each one by one.
 

Verify you renamed the file correctly
You downloaded a test.txt file, but IT MUST BE RENAMED to test.php  If it is not renamed with the extension php, the code will be given to the user instead of computed.

Verify you server is configured with PHP
Goto Start>Programs>Apache HTTP Server 2.0.54>Configure Apache Server>Edit the Apache...

Then go all the way to the bottom where I previously told you to put in the PHP reference stuff...

Image Warning: In my example the PHP reference points to the E drive, this is only because that is where I installed my PHP library, it may be different for you

If it's not there, then copy and paste it in from here:

 
ScriptAlias /php/ "c:/php/"
AddType application/x-httpd-php .php
Action application/x-httpd-php "/php/php-cgi.exe"
 

NOTICE:
You cannot have backslashes in this file.  So having something like "C:\PHP\" is a no-no.  It must be "C:/PHP/" instead.  Just take out all backslashes ( \ ) and replace them with slashes ( / ).

 

Verify you downloaded PHP to where your reference points to
Like in the above step, open your Apache Server .conf file, and go to where your PHP reference points to ont your hard drive.  So if it points to "c:/php/", then goto yu C drive, and then enter the "php" folder.  Then check and verify there is a php-cgi.exe there.  If it's not, then change the .conf file to point to one of the other .exe files there.  I think there should also be a php.exe and a php-win.exe there.  Also keep in mind that when you change you .conf file for Apache Server, the settings do NOT update automatically, nor immediately.  You have to force Apache server to update by restarting the server as shown in the next step.

Image Warning: You most likely installed the PHP library to C:\PHP and not to E:\PHP like I did.  You must keep consistency with where you installed PHP for obvious reasons.
(click for larger image)

then...

RESTART THE SERVER
Don't question me, do it!

There is a very good reason for this. 
And that is to update the Apache settings.  They do NOT update by themselves, when you make a change to the .conf file, the Apache Server will not notice until you restart it.
You can do this by going to START>Programs>Apache HTTP Server>Control Apache Server>Restart
Do NOT use the Start command. Restart is better because even if the server is already on, it will work, using start while the server is on won't.