Pithaly

Paint.NET is free image editing and photo manipulation software designed to be used on computers that run Windows. It supports layers, unlimited undo, special effects, and a wide variety of useful and powerful tools.

If all you want is a quick image retouch, Photoshop is overkill. Paint.NET, on the other hand, is an open-source freeware editor with all the essentials, including tools to crop, rotate, resize images, adjust colors, and create collages.

Paint.NET supports common image formats--JPEG, PNG, GIF, TIFF, and others--but not high-resolution RAW files. There are enough basic and intermediate effects and features to keep image-tweakers happy, though the red-eye removal tool is notably weak; those images may require manual attention.