Lubuntu looks perfect for old hardware. It runs brilliantly on my old inspiron 1300 but there was no network applet at all so I was pretty frustrated getting it on wifi.
There is lots of help on the internet, but it took me a while to realise that the missing network applet was a bug and the fix was easy.
http://www.webupd8.org/2014/04/fix-lubuntu-1404-network-manager.html