With my copy of Office 2000, you can install Microsoft Photo Editor. While Photo Editors are a dime a dozen, Microsoft's is excellent for working with gifs, pngs or tifs. You can do two things with this program that you may not be able to do with other programs.

First, you can resize graphics upwards and downwards and get integral size ratios. This way you can determine the "true resolution" of graphics. We often deal with 320x200 graphics.

With Microsoft's resizer, you can upscale the graphics into 640x400, 960x600, 1280x800, 1600x1000 or 1920x1200, 2240x1400 or 2560x1600. These are the integral scaling ratios of 320x200. More importantly, if dealing with lossless compression file formats, you can get perfect results, i.e. no interpolation. The pixels will be as sharp and distinct as they were in the lowest resolution.

Also with the resizer, you can view the graphics original aspect ratio. As we all know, Sierra AGI and LucasArts' early SCUMM graphics were in a 160x200 mode but appear in a 320x200 mode by doubling the pixels horizontally. If you want to see what the graphics look like using squarish pixels, use the resizer and click the box that says "allow distortion." You will get perfect results, i.e. each pixel halved horizontally. Similarly, if you suspect that a game is using a 640x200 mode and the display adapter is double scaling it, you can use the program to resize the pixels to eliminate every other line, as if you were viewing them on an IBM PC Convertible's screen (which has a 2.6:1 aspect ratio.)

The second great feature is the ability to edit by pixel. To crop or copy, you can use a box that moves one pixel depending on where you move the mouse. Excellent for measuring as well as editing pictures. It is perfect for getting rid of borders and unusued parts of a picture. Normally I use Infranview for image analysis, but I don't like its scaling abilities or its sub-pixel selection.