You can customize puppy linux install to take between 28 to 99 MB. Overall, Puppy Linux is a superb, light-weight, fast and versatile Linux distribution with a great selection of applications, graphical system administration utilities and all sorts of unique features not readily available elsewhere. A great choice not only for older computers, but also for those who dislike the bloat of most modern distributions.

Download ready-to-go live bootable CD iso image here.