En el manual dice
Cita:
Iniciado por http://windows.php.net/download/ Which version do I choose?
If you are using PHP with Apache 1 or Apache2 from apache.org you need to use the VC6 versions of PHP
If you are using PHP with IIS you should use the VC9 versions of PHP
VC6 Versions are compiled with the legacy Visual Studio 6 compiler
VC9 Versions are compiled with the Visual Studio 2008 compiler and have improvements in performance and stability. The VC9 versions require you to have the Microsoft 2008 C++ Runtime (x86) or the Microsoft 2008 C++ Runtime (x64) installed
Do NOT use VC9 version with apache.org binaries
VC9 versions of Apache can be fetched at Apache Lounge. We use their binaries to build the Apache SAPIs.
A lo que entiendo es que versiones de la 5.2 son vc6.