In the process of converting general windows default utilities to “apps”, it seems that almost invariably functionality is lost — often important functionality. The new “Photos” app apparently can’t even show images at 100% zoom with a simple click, and mouse wheel zoom is completely broken. I find that unacceptable.
Luckily, Windows 10 still ships with the old Photo Viewer. Because it’s MS though, that Photo Viewer is not an executable but rather a dll which needs to be hosted and invoked somewhere, so it’s hard to associate with images in Windows 10. To work around this I’ve created PhotoviewerWow.exe. It merely invokes the existing .dll, and should work on Windows 10 64 bit installations. Just put it somewhere permanent and you can easily associate it directly with image files.