I know this sounds kind of nooby, but I got my computer a day ago and tried installing CS:GO from Steam, but my internet speed is very slow. I just wanted to know if I could install it while my computer is off, as I don't really want to be sitting here staring at a bar all day.
You can't. If you want to save energy, just turn off your LCD.
Don't wait until the download is complete, just do your daily life as usual and let your PC do it`s job.
'Fraid not. My net isnt fast either but i put my pc in low power mode, set downloads off and turn off my monitor.
I leave it to run for x hours, or overnight, and check up on it later.
To improve power consumption further, ensure no unneeded programs are running as they can cause the system to use more power (you know, cpu usage goes up, which requires more electricity and so on.)