IrfanView is a very fast, small, compact and innovative FREEWARE (for non-commercial use) graphic viewer for Windows 9x/ME/NT/2000/XP/2003/Vista.
It is trying to be simple for beginners and powerful for professionals.
IrfanView is trying to create new and/or interesting features in its own way, unlike some other graphic viewers, whose whole "creativity" is based on feature cloning, stealing of ideas and whole dialogs from ACDSee and/or IrfanView! (for example: XnView has been stealing/cloning features and whole dialogs from IrfanView, for 7+ years).
http://www.irfanview.com/