Windows 10 does not give users direct access to the system lock timeout setting. You can dig around the Settings app and the Control Panel app and you won’t find anything that lets you pick when the system should lock automatically. The only workaround to this is to use the screensaver which is still a feature on Windows 10. You can enable it and when enabled, it will also automatically lock Windows 10.
While this works and is the simplest way to automatically lock your system if it’s been inactive for a certain period of time, it has shortcomings. The screensaver may prevent certain scripts from functioning if those scripts target the power options on your PC. In that case, you’re going to have to edit the registry and change the Windows 10 system lock timeout.
Windows 10 system lock timeout
Tap the Win+R keyboard shortcut to open the run box. In the run box, enter the following, and tap enter.
This will open the registry editor. In the registry editor, go to the following location.
Under the System key, look for a value called ‘InactivityTimeoutSecs’. It is possible that this value does not exist. In that case, you’re going to have to create it yourself.
Right-click the System key and select New>DWORD (32-bit) value from the context menu. Give the value the following name.
Double-click it and in the box that opens, select the ‘Decimal’ base system. In the value data field, enter in seconds how long the system lock timeout should be. For example, if you’d like the system to lock automatically after five minutes of inactivity, you will enter 300 (60×5). Click Ok, and then restart your system.
The system will now lock automatically if it is inactive for the period of time you set in the registry. You can change the interval any time you want but, you will have to restart the system after each change for it to be applied.
It’s mind-blowing that Windows 10 doesn’t have a simpler, more direct way to manage this setting. You will find that there are several other power-related settings that are hidden by Windows 10. You can only enable them by modifying or adding values to the Windows registry.
If you do not set a system lock timeout, Windows 10 will not lock even if the display has gone to sleep. It will lock only when a certain amount of time has passed. If the value was missing from the registry, to begin with, it is possible that your system wasn’t locking at all unless it went to sleep.