The Make Tech Easier site offers a short post titled How to Build a Lightweight Linux for your Low-End Laptop on why and how to use Debian to set up an older laptop. I've used Debian many times to get old hardware running and, like the author of this entry, Joshua Price, I find the flexibility and lightness of Debian really helps the Linux distribution live up to its billing as "The Universal Operating System," which can run well on many different kinds (and eras) of hardware.