Windows 7 – Reduce power use on computer

I watch a lot of movie’s on my computer which is connected to my TV. Problem is i built the pc to be a gaming computer and it has the power supply to match (1200w).

Is there a way to set it into a “Low power mode” whilst i am playing a movie to use as little power as possible.

I am running – Windows 7 Ultimate 64bit
VLC for playing movies
Connect to my TV via a standard HDMI cable

Solution:

If this post is correct, then you may not be using as much power as you thought when playing movies. If you want to verify that for yourself, you could always borrow or buy a Kill-a-Watt or similar inline power meter and see how much the PC draws during different activities.