I just recently needed to install PHP on my development machine, which has Vista Home Premium on it. I downloaded the installer version of PHP5 from the website and ran it. It killed my IIS process and didn’t hook up to PHP extensions. Every 5 minutes, I’d get a IIS process stopped working message.
After searching the net for a good tutorial on how to install PHP on Vista, I found the following from an engineer at Microsoft. It worked like a charm:
http://blogs.iis.net/bills/archive/2006/09/19/How-to-install-PHP-on-IIS7-_2800_RC1_2900_.aspx
You’ll need to download the zip version of php, not the installer, here:
http://www.php.net/downloads.php