In theory Windows should be able to shut down a PC when it’s been idle for a while, and even if that doesn’t work for you, there are plenty of tools around which promise to do something similar. In practice, though, the difficulty of detecting idle time accurately means that these tools aren’t always reliable, which is why many people take the safer approach of leaving their system running all the time.

AllOff is a little different, though. This free (for personal use) tool doesn’t just shut down your PC after some fixed period of time, or when your keyboard or mouse haven’t been used for a while. It also monitors CPU usage, even download speeds, and provides a host of configuration options to ensure everything works just as you require.

After a slightly more complex installation than usual (you have to register the program with your email address), AllOff presents its default console. It’s not exactly going to win any interface design awards, but this does provide all the key details you need. So you’ll see that by default your system will close if there’s no activity for 10 minutes; an “idle” counter will show you how close you are to that figure; and a couple of figures for your CPU usage and download rate highlight any current background activity.

Click Config, though, and you’ll find the program’s settings, which is where life gets much more interesting.

The program's interface is basic, but easy to use

By default AllOff will calculate your average CPU usage over 5 seconds, for instance, which makes it less likely that the idle count will be reset by a brief spike in activity. But you can adjust that averaging time to anything from 1 to 30 seconds, as well as setting a minimum CPU usage figure which you’d consider as idle, to make the program even more accurate.

You can set the minimum download rate, which again aims to prevent the idle count being reset unnecessarily (when some update checker briefly connects to its website, for instance).

AllOff will also leap into action if your mouse and keyboard have been inactive for your preferred period of time.

And there’s plenty more. You could enable only some of these idle detection methods, say, perhaps ignoring the CPU check and using only download rate, keyboard and mouse monitoring. You’re able to have the program control a remote PC. There are multiple logging and console display options (minimise to the system tray, set the AllOff window to be “always on top”). And of course you can choose your preferred action when the program does finally activate (Hibernate, Log off, Power off, Reboot, Shutdown, Standby).

Even at this final point, though, AllOff still gives you choices. So you can have your system power down in a couple of seconds. But if you’d prefer to be cautious then you can have the program display a warning alert for up to 10 minutes, giving you time to cancel the shutdown, while clearing the “Force” checkbox means open applications won’t be forced to close.

You don’t have to get into any of this complexity at first, of course – in our experience the default settings worked very well. But, if you do have any problems, AllOff’s extensive configuration options should help you fine tune its performance, and it certainly earns a thumbs up from us.