Power Management have been around since the first laptop was released to the main stream. For some strange reason power management have always had a lot of child diceases (crashes, slow-downs or just not saving power).

There are different commands available to diagnose power management issues:

• What devices can wake the computer from sleep mode:

  powercfg -devicequery wake_from_any

• What devices can wake the computer from standby:

  powercfg -devicequery wake_armed

• Disable a device ability to wake the computer:

  powercfg -devicedisablewake "device name"

• Make a device able to wake the computer:

  powercfg -deviceenablewake "device name"

New Vista Commands

• What device caused computer to wake from sleep mode:

  powercfg -lastwake

More Info MS Technet - Powercfg Command-Line Options

New Windows 7 Commands

Windows 7 introduces some new commands, and if installing Win7 on a laptop, then one should try out the following commands:

• Analyze the power comsumption of the computer, and lists devices with issues:

  powercfg -energy

• Diagnose why the computer is not able to enter sleep mode:

  powercfg -requests

More Info MS KB976877

Credits The Old New Thing