Currently under "settings" you can choose to have the CCleaner automatically run when you first power your system on. I would like to see an option added so that it automaically runs on the power down. I know when I power-up my computer it is usually because I am in a hurry to do something with it and don't have the time to sit and wait for it to do its thing. After I have completed my work and powering down for the day it can take all the time it needs to do its thing as long as it automatically powers my computer off when its completed.
Hi Glenn, and welcome to Piriform.
CCleaner can already do that via it's "Auto Shutdown" feature:
http://forum.piriform.com/index.php?showtopic=16551
I have it configured to a shortcut in my Quick Launch Bar. One click cleans and shuts down.