The PHP SDK requires version 5.4 of the php-cgi.exe binary.
You can get the required binary by downloading the "VC9 x86 Thread Safe" ZIP file from the PHP Windows Release site.
Once the ZIP is downloaded, you should extract it to a convenient location e.g. c:\Users\<UserName>\php.
At this point php-cgi.exe (the binary used by the PHP SDK) can be found at c:\Users\<UserName>\php\php-cgi.exe.