Hmm...
The task scheduler is just a series of next buttons,
and it's not hard to create a batch file with the line that I suggested above and schedule that...
the only other way I can think of how to do this would be to download some sort of program that would do it for him.
or to click start, press run and typ shutdown -i
then he cuold set the shutdown time before he goes to bed, (assuming he's manually statring the downloads.
assum you go to slep at midnight, set thecomputer to shutdown, and set the delay (in seconds for)
5 (hours) *60 (minutes) * 60 (seconds) = 18000 seconds...
then five hours later, (once you are sleeping) your computer will shut it's self down,
this is probably better in some respects because,
a) you get to tell it when to shutdown, if there is three hours left on your download, you can make it turn off in three hours rather than five.
b) it won't turn off when you don't want it to, (e.g if you've gotten up early to complete an asignment and forgotten that yuo'd scheduled that task.