Microsoft KB Archive/927821

= A computer that is running Windows Vista appears to sleep and then immediately wake =

Article ID: 927821

Article Last Modified on 3/15/2007

-

APPLIES TO


 * Windows Vista Enterprise
 * Windows Vista Business
 * Windows Vista Home Premium
 * Windows Vista Home Basic
 * Windows Vista Ultimate
 * Windows Vista Enterprise 64-bit edition
 * Windows Vista Business 64-bit edition
 * Windows Vista Home Premium 64-bit edition
 * Windows Vista Home Basic 64-bit edition
 * Windows Vista Ultimate 64-bit edition
 * Windows Vista Starter

-



SYMPTOMS
When you try to put a computer that is running Windows Vista to sleep, the computer appears to sleep and then immediately wake.

This problem may occur when you use the Start menu, a sleep button on a keyboard, or a Microsoft Windows Media Center remote control.



CAUSE
This problem occurs when you use the following two devices:
 * A USB device that supports the wake from sleep functionality of a keyboard, mouse, or Media Center infrared (IR) receiver
 * A USB Universal Host Controller Interface (UHCI) host controller that does not support the wake from sleep functionality

This problem occurs when this USB device is connected to the UHCI host controller. This problem occurs even when the system BIOS reports that the UHCI host controller supports the wake from sleep functionality.



WORKAROUND
To work around this problem, plug the USB device into an Enhanced Host Controller Interface (EHCI) host controller.

Alternatively, disable the USB device's ability to wake the computer. To do this, follow these steps:
 * 1) Click Startvistastartbutton.jpg], right-click Computer, and then click Manage.
 * 2) In the User Account Control dialog box, click Continue.

If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
 * 1) Click Device Manager, expand Universal Serial Bus controllers, right-click the device, and then click Properties.
 * 2) Click the Power Management tab, disable the Allow this device to wake the computer check box, and then click OK.

Note We recommend that you use the first workaround because it preserves the wake functionality. When you use the second workaround, USB devices cannot wake the computer. Additionally, the remote control power button for a Windows Media Center IR receiver cannot wake the computer.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
When the computer goes to sleep, USB devices turn off. The UHCI host controller interprets this event as if the USB devices are unplugged. Then, the UHCI host controller wakes up the computer.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

841858 Description of how to enable the S3 system power state for standby when USB devices are armed for wake

Keywords: kbtshoot kbexpertisebeginner kbprb KB927821

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.