This chapter investigates how to support Power Management in WDM device drivers. NT style drivers in Windows 2000 and Windows 98 can also support Power Management. A device can change its power usage in response to system power state changes, and can reduce its own power usage when it has been idle for a while. A sleeping device can wake the system up, such as when a modem receives an incoming call.

The Power Management aspects of the example Wdm2 driver are explained. The Win32 application Wdm2Power can be used to test Power Management facilities.