To overcome this kind of scenario, the best option is to use a software that automatically shuts down your computer at a specified time. Earlier I used to use the PC Auto Shutdown software from GoldSolution Software which is a good software with all the options like adding multiple time slots to shut down your computer, an abort pop up to cancel the shut down task but its not a freeware and not all can buy the paid software.
I work on many computers to fix them, sometimes I start a task that takes a long time to get completed and I cant be in front of the computer to wait for it so I was in search of a good free software to turn off the computer at a specified time and I found one from WinMend. You can download the software free of cost from the below link
Click Here To Download WinMend Auto Shutdown Software
The software has four options to choose from, either you can Shut down, Log off, Stand by or Hibernate your computer depending upon the requirement at that time. You can either make the settings to daily or can specify a particular date and time to turn off your computer. Once you have setup the options just click on the start task button at the bottom right to begin the process. You can also change the color of the user interface as per your wish from the given options at the top right.
At the specified shut down time before your computer turns off, it will show a pop up and you can cancel the task anytime by clicking on the desired button
This software has all the required features, as expected in a free auto shut down software. If you use any other software that you think is much better than this, do let us know what extra features that software has got in comparison to the WinMend`s free software so that we can share the same with our readers.