GreenIT

Users can save energy by putting computers into Sleep mode when they're not in use. With earlier versions of Windows, administrators could use Wake on LAN (WOL) to wake the computer so that it could be managed across the network. However, WOL only works when computers are connected to wired networks. Wireless computers in Sleep mode cannot be started or managed across the network, allowing them to fall behind on configuration changes, software updates, and other management tasks.

Windows 7 adds support for Wake on Wireless LAN (WoWLAN). With WoWLAN, Windows 7 can reduce electricity consumption by enabling users to remotely wake computers connected to wireless networks from Sleep mode. Because users can wake computers to access them across the network, IT can configure wireless computers to enter the low-power Sleep mode when not in use. This also benefits users who need to connect to their computer when working remotely.

Wired network connections use power when they're enabled, even if a network cable isn't connected. Although administrators could disable the wired network connections on mobile computers to save power and improve battery life, users would need to re-enable the network connection before connecting to a wired network. This might leave mobile users frustrated when they attempted to connect to a wired network-for example, in a hotel that did not offer a wireless network connection.

Windows 7 offers the power-saving benefits of disabling a wired network connection while still allowing users to connect to wired networks. Windows 7 can reduce energy consumption by turning off power to the network adapter when the cable is disconnected. When the user connects a cable, power is automatically restored.