Hi Syrinx77,

There is no default option for shutting down the computer after a specific time-frame in Power Options. You can put the laptop in hibernation mode wherein it actually shuts down and does not use any power. However, before doing so, it saves all the current settings to a special file on the hard drive. That way, when you power the computer back up by pressing the power button, you will be returned more quickly to the desktop exactly as you left it.

However, there is another way of doing it. You can schedule a task for automatic shutdown. Here is the link on how to schedule a task for automatic shutdown.

If you want to put the computer in hibernation mode, click Start>>Control panel>> select 'Switch to Classic View' and select "Power Options">> go to 'Hibernate' tab>> check the box ' Enable hibernation'. Hereafter, select 'Power Schemes' tab. Choose the options to suit your needs. Please ensure that the hibernation time is less than your battery time. Otherwise, your battery will drain before the option can kick in. Refer to the images: Power options, Power Schemes

Hope this helps.
Please revert for clarification.

Thanks and Regards,
Manpreet C