ASELAbe has made a guide about how to extend the life of old computers using Damn Small Linux.
Read it here.
The oldest computer I have is a Pentium 266 MMX laptop with 64MB of RAM. Most people would just consider this to be garbage and junk it, and if you brought this in for service where I work, I would agree with you. While this laptop might seem old and out-of-date now, it is small and light. I needed something I could easily carry around, so I figured I would see what I could salvage out of this dinosaur. Windows would have a hard time running on this low-spec laptop, but there are many distributions of Linux that will work exceptionally well. The one we'll be using today is Damn Small Linux.