Again I’ll assume you have PHP downloaded. Extract the new version to a working directory. You should now have a folder called php-5.x.x with x.x being the PHP version number.
Copy that diretory to where ever you installed php. If that is C:\php or if you followed my installing PHP tutorial it will be C:\Inetpub\php-.x.x.x.
Once you have the dir copied you’ll want to edit php.ini.recommended. You can use you current php.ini as a guideline. Once you have the paths and extensions set how you want it then rename it to php.ini.
So that your website uses the new version of PHP we’ll edit the path variables and reset the PHP mime types with IIS Manager.
Set the path using this procedure.
In the bottom box select Path and then Edit button. At the end of the Path variable add ;C:\Inetpub\php-5.x.x. If the path for PHP is already set then just change x.x.x to reflect the new version number.
The last thing to do in add a new path variable.
Click the New button. In the Variable Name field put PHPRC. In the Variable Value field put C:\Inetpub\php-5.x.x. Again of you already have this variable then just change x.x.x to the new version number.
Once you’re done setting the path then click close and apply.
The last step is to open IIS Manager and set .php extension for your website to use the new binary.
Open up IIS Manager. Start > Administrative Tools > Internet Information Services (IIS) Manger.
In the left pane click on Web Service Extensions. Click on the PHP extension. On the box that pops up click required files tab. Remove the old ISAPI filter. Now cclick add and set it to use the new ISAPI filter. If you use CGI then change it to that.
Right click the website and select properties. Click on the Home Directory tab and select configuration button. Scroll down the PHP extension and click edit. Change the path to the new binary. Do this step for each website on the server.
Restart IIS and you’re done.
One note. If you are upgrading to php-4.x.x copy all files from the dll folder into the php root folder. After you are done with the upgrade you should restart the server. IIS caches dlls so the older PHP dlls will still be running. You have to reboot to clear the cache. After reboot check your sites. If you encounter any errors use the comment section and I’ll help you troubleshoot. You can also catch me at The Admin Zone Forum. You can post a question in the Server Configuration forum. It would be best to use the comment section of this site since I am emailed when ever someone posts a comment to any article.