Problem: Installed PHP 5.3.5 onto a newly configure Windows 2008R2 server using both manual configuration and the MSI configuration. When trying to execute the phpinfo.php file, I would get an internal server error. Tried reinstalling, rebooting and reconfiguring with no luck….
Solution: Read on PHP.net that not only do I need to install the VC9 binaries for IIS7 but I also have to download and install the Non Thread Safe bundles as well. I reinstalled using the Non Thread Safe bundles and PHP was working perfectly on the server.
Links: http://php.net/manual/en/install.windows.iis7.php