This is the GTK+ Runtime Environment Installer for Windows. It includes all of the files required to run GTK+ applications on Windows. Some support tools are also available.
Worked fine once I'd sorted out an Entry Point Error problem with zlib1.dll: The installer adds "C:\Program Files (x86)\GTK2-Runtime\bin" to the system PATH variable but this may already be pointing to an existing (and out-of-date) version, in my case the pre-installed and potentially common "c:\Program Files (x86)\Common Files\Roxio Shared\DLLShared\" Solution: search system for zlib1.dll and check to see if PATH points to any older versions. If so you must move the newly-added string to before these references so the new version is found. Leave the old reference alone; it may be required for more than zlib1.dll. Apart from that, no problems at all.
Are there any plans to build more recent version of gtk+2? That is 2.24.25 as of moment of writing? The currently "latest" version in fact is 3 years old. Many bugfixes were commited since then.