The number of programs, most being "free", that will suffice are, well, huge. In Vista, Photo Gallery and Paint work, as does just opening a photo (say, in jpeg, bmp, tiff or whatever), and then selecting among the options for saving the image. Picasa is easy, and a free download in basic form. Most CD or DVD "burner" programs (say, NERO) have file compacting options. Basically, whatever you have pre-installed on your computer usually contains something that will work, and if not then there are a number of free, downloadable programs that will suit your needs. Heck, even my camera comes with a program that will suffice.