Installing PHP 5 on IIS in 5 simple steps


2. Set Your Environment Variables

For this step we'll need to use the Windows GUI, so rather than just write out all the steps I'll use images to do most of the talking.

  • Right click on the My Computer icon and select the properties menu item. You should be presented with a window as shown below in figure 1. Select the Advanced tab and then click the Environment Variables button at the bottom.

Figure 1

  • Scroll through the System variables list at the bottom until you come to the path variable. Select it and then click the edit button as shown below in figure 2.

figure 2

  • Move to the end of the text in the Variable value field and type in the path to the PHP directory you created earlier in step 1 (e.g. D:\PHP). Make sure that there is a semi colon (;) separating the new value you're entering and the previous one, and also place another semi colon (;) after as shown below in figure 3. Once you have added the path click on the ok button to save it and return to the previous window.

figure 3

  • This time we need to create a new environment variable. From the Environment Variables window click on the New button towards the bottom as shown below in figure 4.

figure 4

  • You should now see the New System Variable window as shown below in figure 5. In the Variable name field type in PHPRC, and in the Variable value field type in the path to your PHP install directory (e.g D:\PHP) as shown below. Once done click the ok button to create and save the variable. This PHPRC variable tells Windows where to look for your php.ini file, and if it doesn't find it there or if this variable is not set then IIS will look though your Windows system path.

figure 5


Anonymous's picture

Truely 5 Steps and very easy

Thanks for a superb article. Read a few articles on installing PHP on IIS but couldn't get it done. This one did the trick.

Anonymous's picture

Thanks a lot, its easy and

Thanks a lot, its easy and nice article
Only one extra thing i did i repeated first part of the 3rd step for my virtual directory as well.

Anonymous's picture


So, I've got everything working with PHP using this guide, and the site I made works great!

However, I was wanting to extend the site to add an email verification thing (you know, where you have to click some link emailed to you to verify you're a person), and I was using the 'mail' function PHP has.

This is the first time I've ever touched email from PHP, so this may have NOTHING to do with IIS (It's Windows 2000 Server, so using IIS 5.0) and entirely to do with my naivety, but I can't get email to work. Here is my code:

$mail = mail('', 'Hello, world!', 'This is a message from PHP. Neat, huh?');

if ($mail == TRUE) {
printp('Mail sent!');
} else {
printp('Mail fail.');

How would I get this to work? The email address there was edited, in my actual page it's using my own personal email address.

I have IIS's SMTP service installed, but I don't know how to configure that either. I've never touched email serving before, so this could really be just me being naive.

Anonymous's picture

You are a star

Mate, I don't know how many years ago have you posted this useful information. I was trying to learn PHP through a book, but their instructions to install PHP in IIS didn't work and I was stuck. This was just WONDERFUL information from you. Thank you very very very much.

Anonymous's picture

Is PHP5.3 much different when installing?

Excellent tutorial. I am getting an error in phpmyadmin -
Your PHP MySQL library version 5.0.51a differs from your MySQL server version 5.5.12. This may cause unpredictable behavior.

So I guess I need to upgrade PHP, or downgrade MySQL. Do you agree?
Is there any chance you will be posting instructions for installing PHP 5.3 on IIS? I tried following the same instructions but it doesn't work :(


Brashquido's picture

No ISAPI in PHP 5.3

You'd be correct with your guess. PHP 5.3 is a pretty big change from PHP 5.2, one of the most notable changes was the ISAPI interface (which is used in this guide) was dropped from the package. I will be creating an install guide, however it may be a month or two off yet.

Dominic Ryan
6 x Microsoft IIS MVP, MCSE, MCSA
IIS Aid owner/webmaster

Anonymous's picture

Excellent Doc - Thanks

It solved my problem on IIS5. Step by Step useful instructions.

Thanks a lot,

Anonymous's picture

Getting error: Execute Access Forbidden

I did everything as stated here, but i am getting following error. Kindly help.
HTTP 403.1 Forbidden: Execute Access Forbidden
Internet Information Services

Anonymous's picture

PHP installed by WAMP to be configured in IIS 5.1

Before i start following the tutorial, i would like to clarify whether I can follow these steps if I have the php instance installed in my system through WAMP.
I have the WAMP server running and my php directory resides in C:\wamp\bin\php\php5.3.5

Please guide me..
Thanks in Advance


Anonymous's picture

PHP5Isapi.dll is not available in PHP 5.4

i tried to do installation with this article, but unfortunate that the downloaded php 5.4 do not contain the php5isapi.dll file.
also the PECL Win32 binaries is not found on php download site.

how can i complete this installation! can anyone suggest?