In the past 10 years (or so), I've been taking old
computers (desktops, laptops), and putting Linux on them.
Mainly because Microsoft's philosophy with Windows is a very one size fits all approach, and also because Windows had a general bad reputation when it comes to old machines (security holes, anyone?).
As for friends & family, it was also very difficult for me to convince them that if they'll switch, they could get 2+ more years out of their machines.

The reaction usually was "But what about my Word? and all the other software (i.e. Mine Sweeper) I always use?".
I must say, in 2013 there's very little resistance for suggesting someone to switch an OS.
This is because over 90% of our time on the computer is done with the Browser these days.
Browsers are mostly OS agnostic, you can get them on Linux too.

All the plugins, bookmarks, etc. are synced without an issue, and the only things
that still need to be taken care of are the drivers (that somehow almost never work 100%).

Sometimes it's a game of russian roulette, sometimes you get to operate your WiFi card, and sometimes the system insists that there's a Hardware Block on it even though another Linux Distribution connects without a problem.

There's a tendency to spend hours upon hours on Linux in order to solve issues, but there are 2 good things about that:
1. You get to spend those hours because you can (usually) actually fix the issue eventually, instead of just accepting the bug as it is.
2. Almost always this happens on a fresh install, in case some driver won't work, so it's a one time thing.

Nothing can be compared to getting an old laptop working again, enough to surf rather fast, and do everything that needs to be done.
If all else fails (and I'm talking to the developers among you), make it a Cloud Server, add some cool automations, connect it to Raspberry Pi, go nuts!

Next post will be about Web Dev, I promise.