Power Saving
Power saving settings on Windows Vista PCs
PCs running Windows Vista are configured to minimise their use of electrical power. The power saving settings are those provided within the Windows Vista operating system.
After five minutes of inactivity the monitor will power off, and after thirty minutes of inactivity the computer will "hibernate". To wake up your computer before the thirty minute time limit, you need to move the mouse and/or press any key on the keyboard.
Hibernate consumes very little power, almost as little as switching the computer off completely, but you can resume normal operation much more quickly without having to wait for the PC to go through the entire start-up process.