A quick tweak of the power options and you can soon have your PC set up to shut down automatically if it’s left unattended for a while. But Windows isn’t exactly smart about how this happens, and you may sometimes find your system is closed even if it’s busy downloading something, or running some lengthy CPU-intensive task.

Install SmartPower, however, and it’s a different story. The program allows you to create far more flexible rules about when your PC should sleep, and when it needs to wake up, which can be a great way to save you time, energy and money.

Click the SmartPower “Networks” tab, for instance, and you’ll see that the program will by default keep your PC awake if network traffic on the selected interface is above a given threshold (15kbps initially, though you can set this to whatever you like).

SmartPower can block shutdowns when you're downloading, or your CPU is unusually active

It’s probably a good idea to enable CPU checking, too. Click the CPU tab, check “Stay on when CPU usage is above a threshold”, and set that threshold to a suitable figure (if you’re unsure, the default 10% is probably a good place to start).

Click the Devices tab and you can also instruct SmartPower to stay on when other network devices are working. Which could be ideal if, say, you’ve a NAS device which you’ll normally turn off last thing at night: SmartPower can recognise its presence (or absence) and react accordingly.

There are several other useful options. SmartPower can be told to keep your PC on when another program is requesting display or system power, for instance, handy for spotting applications playing videos (for instance). While the Processes tab allows you to specify particular processes which mustn’t be interrupted by a system shutdown.

And if your system passes all these rules and is able to shut down, then SmartPower’s schedules can also automatically wake it up again at the time you specify (as long as your hardware is up to it, anyway, which should be the case with most modern PCs).

Put it all together, then, and SmartPower is an excellent free-for-personal-use solution to the usual Windows shutdown inflexibilities. If you’d like to take more control over your PC’s energy use then it’s a great way to get started.