I was wondering if there was a way to go into a low power mode on Vista Premium 32bit for streaming videos.

It seems kinda silly to have a computer fully on when I just need my 360/ps3 to tap the harddrive to stream videos with tversity and playon.

I know a NAS is kinda what I'm talking about but I don't really want to invest in new hardware and don't really have room for it. So if there a was a way to go into a low power mode while keeping a media server active I would be interested in it.