Microsoft KB Archive/935799

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Article ID: 935799

Article Last Modified on 10/31/2007



APPLIES TO

  • Windows Vista Ultimate
  • Windows Vista Enterprise
  • Windows Vista Business
  • Windows Vista Home Premium
  • Windows Vista Home Basic
  • Windows Vista Starter
  • Windows Vista Ultimate 64-bit Edition
  • Windows Vista Enterprise 64-bit Edition
  • Windows Vista Business 64-bit Edition
  • Windows Vista Home Premium 64-bit Edition



Important This article contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry


SYMPTOMS

When you configure power options for the active (current) power plan in Windows Vista, the changes are not reflected on the System Settings page in the Power Options item in Control Panel.

This behavior does not occur if you are currently using the default, or "preferred," power plan. The preferred power plan is specified in the registry.

CAUSE

This behavior occurs because the settings that appear on the System Settings page are derived from the registry settings for the preferred power plan.

Changes that you make to the active power plan do not affect the global settings on the System Settings page, unless you are currently using the preferred power plan. Changes that you make on the System Settings page apply to all power plans. These power plans include the active plan and any custom plans that you have created.

Note By default, the preferred power plan is the Balanced plan in Windows Vista.

MORE INFORMATION

Power plans

Power settings in Windows Vista are based on power plans. A power plan is a collection of hardware settings and system settings that manages how your computer uses power. Power plans can help you save energy, maximize system performance, or achieve a balance between these two goals. Windows Vista provides the following default plans to help you manage your computer's power:

  • Balanced

This plan offers full performance when you have to have it. This plan saves power during periods of inactivity.

  • Power saver

This plan saves power by reducing system performance. This plan can help mobile PC users benefit the most from a single battery charge.

  • High performance

This plan maximizes system performance and responsiveness. Mobile PC users may notice that battery power does not last as long when they use this plan.

You can change settings for any of these plans, or you can create your own plan by using one of these plans as a starting point.

How to create a power plan

To create a power plan, follow these steps:

  1. Click Start [GRAPHIC: Start button ], type Power Options in the Start Search box, and then click Power Options in the Programs list.
  2. On the Select a power plan page, click Create a power plan in the task pane.


[GRAPHIC: User Account Control permission ] If you are prompted for an administrator password or for confirmation, type your password, or click Continue.

  1. On the Create a power plan page, select the plan that is closest to the type of plan that you want to create. For example, if you want the plan to conserve energy, select the Power saver plan.
  2. In the Plan name box, type a name for the plan, and then click Next.
  3. In Change settings, select the display settings and the sleep settings that you want the computer to use when it is running on battery power and when it is plugged in, and then click Create.


If you are using a mobile PC, your plan appears under Plans on the battery meter. If you are using a desktop computer, your plan appears under Preferred plans.

Note The plan that you created automatically becomes the active plan. To put a different plan into effect, select that plan on the Power Options page.

How to customize a power plan

To customize a power plan, follow these steps:

  1. Click Start [GRAPHIC: Start button ], type Power Options in the Start Search box, and then click Power Options in the Programs list.
  2. Click Change plan settings under the plan.
  3. On the Change settings for the plan page, select the display settings and the sleep settings that you want your computer to use, or click Change advanced power settings to change additional settings.
  4. Click OK, or click Save changes to save the changes.


Make sure that the power plan that you want the computer to use is selected on the Power Options page.

How to use the Powercfg.exe tool to set the active power plan

You can use the Powercfg.exe tool to control power settings and to configure computers to use the hibernate feature or the sleep feature. The Powercfg.exe tool is installed with Windows Vista.

To set the active power plan by using the Powercfg.exe tool, follow these steps:

  1. Click Start [GRAPHIC: Start button ], click All Programs, and then click Accessories.
  2. Right-click Command Prompt, and then click Run as Administrator.

    [GRAPHIC: User Account Control permission ] If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
  3. Type the following command, and then press ENTER:

    Powercfg -setactive Scheme_GUID

    Note Scheme_GUID represents the scheme GUID. To determine the GUID for all existing power schemes, type Powercfg /List at the command prompt, and then press ENTER.

For more information about the Powercfg.exe tool, visit the following Microsoft Web page:

How to use the registry to set the preferred power plan

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

To change the preferred power plan, follow these steps:

  1. Click Start [GRAPHIC: Start button ], type regedit in the Start Search box, and then click regedit.exe in the Programs list.

    [GRAPHIC: User Account Control permission ] If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
  2. Locate and then click the following registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\explorer\ControlPanel\NameSpace\{025A5937-A6BE-4686-A844-36FE4BEC8B6D}

  3. Right-click PreferredPlan, and then click Modify.
  4. In the Value data box, enter one of the following:
    • Type 381b4222-f694-41f0-9685-ff5bb260df2e to use the Balanced plan.
    • Type a1841308-3541-4fab-bc81-f71556f20b4a to use the Power saver plan.
    • Type 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c to use the High performance plan.
    You can also type the power scheme GUID for a custom power plan that you have created. To determine the GUID for all existing power schemes, type Powercfg /List at the command prompt, and then press ENTER.
  5. Click OK, and then exit Registry Editor.


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