HD Install :: How to save settings with a full HD install?

How do I save my settings when I have a full HD install of DSL? I´m a complete newbie to linux i general and DSL specificly. The tips and hints on saving settings given in the quickstart guide in dillo only seem to concern frugal and live-cd installs. I want to change my background image but everytime i restart x the original background image appears.

original here.