You have to use Windows' power options. I have mine set so windows puts the computer into hibernation after 15 minutes of inactivity. It usually works, but on certain occasions it fails. I still haven't figured out why. Not a big deal, though, I can always force it into hibernation.
GBPVR will wake the computer up at the time a recording starts. Just remember that you need to have prepadding on to allow for the computer to wake up. You will also want to make sure you have the "wake up computer for EPG update" (or something like that) box checked in the config app.
In the Config program, at the very bottom of the Capture Sources tab, make sure that you have some number like 2 or more in Minutes pre-show padding.
GGF