There are occasions when it is necessary to leave the computer turned on even in our absence, so as to complete a longer operation (rendering of an image or conversion of a video) or a particularly heavy download.In all these cases it can be useful to set the PC to lock and go off after a certain period of time, also using programs capable of automatically shut down the computer after a certain period of inactivity or when the process of a process has ended.
In this guide we will show you both the energy saving settings offered by Windows 10 and some useful programs to turn off the computer after a certain period (obviously we try to set a sufficiently long period, so as to cover the entire activity that we leave in abeyance) .
READ ALSO: 8 Programs to shut down the computer automatically with a timer
Windows power saving settings
Windows 10 offers various settings for saving energy, so you can turn off the monitor and then hibernate the PC after a programmable period of inactivity. The settings are valid both for fixed PCs and for laptops (on the latter it is even more useful to set these "timers" to save battery).
First let's take us to the Start menu at the bottom left and open the app Settings (this menu is also accessible from the gear icon). Once the settings panel is open, let's take the path System -> Power supply and suspension. 
From here we can configure the switching off of the monitor and the subsequent suspension of the computer after a certain period of inactivity, modifying the various parameters proposed. In order to obtain a good compromise between waiting time and execution of the suspension, we advise you to set the parameters as follows:
Screen section
- If powered by battery, it deactivates later 10 minutes
- If connected to the mains, it deactivates later 20 minutes
Suspension Section
- If powered by battery, the PC goes to sleep after it 15 minutes
- If connected to the mains, the PC switches to the suspend state afterwards 30 minutes.
To lock the PC up to our return, we configure an access password by taking us to Settings -> Account -> Access Options. 
We can also configure the dynamic lock, so that we can lock the computer as soon as we leave the station (using the Bluetooth connection between phone and computer).
The same entries can also be configured on Windows 7 and Windows 8.1, opening the Control panel -> Hardware and sound -> Power options and clicking on the item Change computer sleep settings. 
Programs to shut down the PC after a certain amount of time
To lock the computer after a certain amount of time we can also use free programs, which can be installed on any version of Windows.
Auto Lock
Auto Lock is a free mini tool for all versions of Windows that allows you to configure PC shutdown or automatic shutdown.
Autolock is a light and simple program to configure. First we can choose between two modes: If Idle is Force.
With the mode If Idle, you can specify a time of inactivity of the computer (that is when the PC does not work on anything and you do not touch either mouse or keyboard) within which the PC must disconnect, it must go off or lock itself with a password. With the mode Force instead the timer is inexorable and when it falls to zero (whatever activity we are doing), the computer will block or turn off.
As settings to execute we can choose whether to turn off the computer (shutdown), whether to block it (lock), whether to disconnect it (Log off) if you restart it (restart) or if you do nothing (the screen will just be turned off). At the same time you can choose to turn off the screen and turn off the computer sounds when the countdown ends. For example, then you can simultaneously select Windows lock and screen darkening.
Autolock can be minimized in the notification area but closed if the X button is pressed in the configuration window. It cannot be set automatically because the start of the timer can only be set manually by pressing the Start button.
This tool is very simple but adds a few more options than the Windows energy-saving settings that can only turn off the screen or suspend the computer.
PowerOff Timer
On Windows 10 we can also install the PowerOff Timer program, available directly from the Store App. 
With this simple program we can set the computer to shut down (but also restart, suspend or hibernate) at a specific time of day (configurable in AM / PM mode).
By setting an operation, a specific time and pressing on the button activate we will be able to start a convenient timer that will turn off or block the PC at the appointed time, without the need to have to be around to complete the operation.
Conclusions
Using the settings offered by Windows and working alongside one of the two recommended programs we will be able to control the shutdown of our computer, so as to prevent it from being accessed too long or someone to use it without our permission. To this we add that many programs offer the possibility to set the computer to shut down at the end of the operation (for example burning programs, rendering programs, video editing programs and programs to download P2P files), so as to have the absolute certainty that at the end of the task the program itself will shut down the computer for us!
In other articles we have seen How to set the PC to turn off automatically with a sleep timer, How to turn off the computer remotely and in another guide we showed you How to shut down your computer with automatic reboot and hibernation.