IrfanView is a fast and compact image viewer/converter. It is trying to be simple for beginners and powerful for professionals.
Many supported file formats and features. Features include: multi-language support, Thumbnail option, Painting, slideshow, toolbar skins, fast directory browsing, batch conversion/editing, multipage editing, file search, change color depth, scanning, cut/crop, IPTC edit, capturing, lossless JPG operations, effects, ICC support, EXE/SCR creating, many hotkeys, command line options and plugins.

Paint.NET is free image and photo editing software for computers that run Windows. It features an intuitive and innovative user interface with support for layers, unlimited undo, special effects, and a wide variety of useful and powerful tools. An active and growing online community provides friendly help, tutorials, and plugins.