If I use the Windows context menu to "edit with gimp" on any image file (it does not need to be a png) GIMP opens up in a old style UI (like Windows 95 look) and throws an error that says "Image type 'png' is not supported" but it does open the image for editing, even if it was a png.
If GIMP is already open, then the context menu functions just fine and no error is thrown.
I am using GIMP 2.6.9 on Windows 7 x64, and while I'm willing to update to a newer version, I will not update to 2.8 or newer, as I dislike the "Export As..." method of saving files as anything other than xcf. I understand why the change was made, I just dislike it. I believe this is the same version I had on my Win7 x86 install.