You can do as ahundiak said and install a wamp type version, it is the easiest way, but if you want to do your own separate installs then read on!
OK I assume you now have Apache running, did you test it, by going to your localhost in the browser, and get the "It Works!" message?
What type of PHP package did you get? if it was the windows installer version, then go back and get the zip version.
If you have the zip version unzip php to a folder preferably c:\php, create a php.ini in the same folder, to do this open up the file php.ini.dist and save it as php.ini.
I will assume that it will be C:\php, don't change anything in it just yet.
Now open the Apache httpd,conf file, which will be in the C:\Program Files\Apache2.2\conf folder, for editing, and paste the following into it (I have used the code for a module installation)
LoadModule php5_module "c:/php/php5apache2_2.dll"
AddType application/x-httpd-php .php
configure the path to php.ini
PHPIniDir "C:/php"
All the paths will have to be changed if you do not unzip PHP into C:\php
Save and then restart the apache server.
Now open your php.ini file for editing and look for the line
doc_root =
change it to
doc_root = C:\apache\htdocs
if you have installed apache anywhere else then change c:\apache for the directory you have used, if you have installed it to C:\Program Files\apache\, then it will need to be within double quotes like
"C:\Program Files\apache\"
to cope with the space in the path.
Save and then restart the apache server, again.
If all goes as it should you should now be able to parse php files through your 127.0.0.1/ address.
You can now go into you php.ini file and change the settings to suit you. Like enabling extensions and setting your extension path.
See here for an overview on windows installs and here for Manual Installation Steps
