You can always set windows to automatically shutdown whenever you want. Like my self, i've always away when downloading movies or series. Here's how to do it..

1.Click Start Button
2.Click Run
3. type at 20:00 shutdown -s
4.Hit Ok 5.DONE! here's some explanation. look no 3, here i set windows to shutdown at 8PM(2000).
if you would like to auto shutdown at 3AM just change the value to 03:00. So,there will be like this

at 03:00 shutdown -s

p/s: If you want to restart just change -s to -r