Hello,
There might be some problem with your Graphic card. Or some kind of hardware problem, your system or monitor heats up when you use it for a long a time. That is why it turns off automatically. So try to fix the hardware of your monitor, especially the picture tube or LCD whatever you have. And in system check the graphic card, its driver and settings. Repair the graphic card and update its driver.
You must check that which windows you are using. Try to update the previous or the best thing is that uninstall it and download the new and latest version from a good source and make sure that your system supports the latest version. Other thing is that there might be some file corrupt or some virus is there which is resisting the running of your game for a long time so try to scan your computer and repair the windows and other files. Do this in normal mode or the best thing is to do it from safe mode.
Have a nice day!
