On his TellingMachine.com blog today Klaus Graefensteiner has a few things you should consider when selecting the right PHP version for your Windows+IIS server.

Questions he suggests will get you started down the right path are things like:

• What version of PHP do I need?
• What CPU architecture is my computer running?
• What http web server is PHP running under?
• What VisualC/C++ Runtime Libraries are the PHP binaries linked against?

If you're looking to run PHP 5.2+ on Windows, you have two main choices - the VC9 version or the VC6 version.