Microsoft claims Windows 7 will have better power management than Windows XP or Windows Vista.
Windows 7 now manages hibernation and standby modes more reliably and efficiently, thus now users would likely be more inclined to use those features rather than leaving the computer on all the time. Furthermore, new IT management and troubleshooting tools are built into Windows 7 to help improve power management. These tools will also help diagnose devices and applications that are causing power issues.
The upcoming operating system is also smarter in power management when idle. Katz said that Windows 7 is better able to manage power saving at times even between keystrokes, which should not only reduce the electricity bill but also stretch laptop battery times.