Quick Picture Viewer is a DotNET viewer with a good coverage of file formats and some basic editing abilities.
[Quick Picture Viewer is a] Lightweight, versatile desktop image viewer for Windows. The best replacement for the default Windows photo viewer.
Ghacks.net review (whose links are getting ridiculous long, BTW ) at:
Quick Picture Viewer latest release (currently v3.0.4) can be downloaded from github.com/ModuleArt/quick-picture-viewer/releases.