when i download my computer shuts sour?

when i download my computer shuts sour?

Did it distribute you any notification that its shutting off? Like something close to "Computer will now restart", if so after that means that the program must hold the OS restart to finish downloading, after that everything should be ok. Otherwise it might just be some downloading error or your computer's psu is discouraging, or its just overheating. Many different possibilities if it isn't of late a standard restart.
you might need to reset your bio on your motherboard by shuttting offf the computer, openeing up your atx overnight case and remove the red jumpers afterwards replace it again if that doesnt work then you probably own a faultymother board that cant take the nouns from the activity so it shuts down the computer