Managed to install PHP version 5.2.11 on a development computer after several evenings of struggle. I previously used PHP 3 and PHP 4 and I don’t recollect any trouble in installing them. PHP 5 suffers from too many options: CGI, ATAPI, FastCGI, thread-safe, non-thread-safe… Having selected one of these, you have to select a manual install or an automatic .msi scripted install. Then you have to select various options during the install.
Then you find it doesn’t work.
PHP forgot to tell you that the installer script doesn’t really complete the installation, and there are further cryptic options you have to find and set. You only find this out by trawling the Web for solutions. Thousands of frustrated people have been there before you.
Then you find it still doesn’t work.
I found several bugs in mine, as follows:
1) php.ini file left over from previous attempt to install in another folder -not helpful!
2) File not found error – caused by IIS pointing to wrong .php location.
3) IIS doesn’t like spaces in path – so enclose path in “” quotes (e.g. “c:/program files/php/php-cgi.exe”) if php directory is in Program Files.
4) Silent time-out when accessing .php file: If you downloaded the cgi option (intentionally or otherwise) it works better if you point IIS at php-cgi.exe not php.exe.
As you’ll have gathered, I’m not at all impressed by this. Obviously this software desperately needs a proper installer that will install a default version and configure it so that it WORKS, as well as offering experts the option to twiddle. Open source at its worst. The developers clearly feel no pressure to make their product user-friendly. They need a kick up the backside.  Microsoft php. anyone?