Installing PHP 5 on IIS in 5 simple steps


Set the PHP Application Mapping in IIS

Before IIS will parse PHP scripts, you must first create an application mapping for PHP. This application mapping basically tells IIS what ISAPI dll, or CGI executable to use to process files of a certain file extension (in this case .php). There are two ways in which we can do this, via the command line or via the IIS MMC snap in. I'm going to show you how to do both.

As this is a universal PHP installation guide for IIS 5.0, 5.1 and 6.0 there are limited universal ways in which to add the PHP application mapping via the command line. What ever you do though do not use the adsutil.vbs script to try and add you PHP application mapping, at least not without understanding it's limitations. When you add/delete an application mapping with adsutil.vbs there is no way you can add/delete a single item at a time. So by using adsutil.vbs to add an application mapping you will effectively delete every other mapping at that level. However, what you can do is use David Wang's awesome chglist.vbs script to add the PHP application mapping without effecting existing mappings. You can download this script from David's old blog or from the bottom of this page. Once you have saved the script, simply open a command window and change into the directory that contains your script and type this in;

chglist.vbs W3SVC/ScriptMaps "" ".php,D:\PHP\php5isapi.dll,5" /INSERT /COMMIT

This will add the PHP ISAPI script map to the root of the IIS metabase, and any sites created after adding this script will automatically inherit it. If you want to add the PHP application mapping to a specific website then you will need to modify the W3SVC/ScriptMaps section of the command to suite. If none of this makes sense at all, don't worry because all this can be done using the GUI as well which we will cover now.

  • Open the IIS MMC and right click on the Web Sites container (or click on any specific website you wish to add PHP to) and select the properties menu item

figure 6

  • Once the Web Sites Properties window opens select the Home Directory tab and click the Configuration button as shown below in figure 7.

figure 7

  • This will bring you to the Application Configuration window. Click the Add button at the bottom to add the PHP application mapping as shown below in figure 8.

figure 8

  • In the Extension field enter .php and then click on the browse button in the top right and select the php5isapi.dll file from inside you PHP installation directory (e.g D:\PHP). The default is to accept all verbs, but if you wish you can limit the verbs to tighten security for you PHP application mapping. Ensure that the Script engine and Check that file exists options as ticked and then press ok until you exit the properties windows.

figure 9

That is it, IIS should now be configured to serve PHP content. There is one exception though and that is if you are using IIS 6 then you will also need to configure a Web Extension, so if you are using IIS 5.0 or 5.1 you can proceed onto the next section. You can set the Web extension via command line using iisext.vbs or via the Gui. Using the iisext.vbs at the command prompt you'll need to type in this, but be sure to change the path to php5isapi.dll to suit your environment ;

iisext.vbs /AddFile D:\php\php5isapi.dll 1 PHP5ISAPI 1 "PHP 5 ISAPI"

To add the extension via the GUI, read on;

  • Open the IIS MMC and expand the server tree. Right click on the Web Service Extensions option and select the Add a new Web service extension option.

figure 10

  • In the Extension name field put in a descriptive name, such as PHP 5 ISAPI as shown below in figure 11. Make sure the Set extension status to Allowed option is checked and then click the Add button.

figure 11

  • In the Add file window click the Browse button and navigate to your PHP installation directory and select the php5isapi.dll file as shown below in figure 12. Then click the ok button until you exit back into the IIS MMC.

figure 12

All done, now your IIS 6 web server is all set to serve PHP content.


Brashquido's picture

Try FastCGI

A lot has changed since I wrote this guide 5 years ago. You are correct, phpisapi.dll has not been compiled for release with PHP since version 5.2. My advise would be to head over to and download the binaries from there. You'll also find links there to some of the PECL binaries compiled for use with later versions of PHP.

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

Anonymous's picture

Getting Not Authorized Error

I am getting following error:

You do not have permission to view this directory or page using the credentials you supplied
HTTP 401.3 - Access denied by ACL on resource
Internet Information Services

The problem occurs for php only,html and works fine.

Brashquido's picture

Check your NTFS permissions on PHP folder

That sounds like your IIS user does not have permissions to access the directory (or subdirectories) where PHP is installed. Your IIS user account will need read permissions in here.

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

Anonymous's picture

Can anyone here tell,, how to upgrade PHP?

Hello everyone,
I have PHP 5.2.1 installed already for about 3 years all running ok, but there are scripts that require higher version of PHP.
For the last 2 weeks I struggle and wrestle all with new versions of PHP to have running, it seems like it is really something hard to make it..
This new phenomenon requires wonder child from MS called fastcgi, good.
Can anyone tell us here how to upgrade to any version higher than PHP 5.2.4 ??
If you refer me to Google,, so I can tell you too, I spent a lot time and tried a lot tricks too,, nothing seems to work, when calling the webpags it says SERVICE UNAVAILABLE, additionally I can see in the IIS Manager ISAPI filters PHP red arrow, although it is set to fast cgi, fcgiext.dll
Thanks a lot for any advice,,

Brashquido's picture

Application mapping rather than filer

FastCGI should be configured as an application mapping rather than a filter. Did you have PHP 5.2.1 configured to use ISAPI?

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