NPS Image Editor is a free, unique image editing program that is perfect for pixel art, drawing, and photo editing. It is lightweight, customizable, and intuitive, yet surprisingly powerful. This version is designed for older systems running Windows 98, XP, Vista, and 7 and requires .NET Framework 2.0; read more on the website.
Adds layer mask support, Magic Wand, Gradient tool, and templates (NPS 4.1.4 feature cut)
Standalone zip archive that does not require installation or admin rights