When you try to put a computer that is running Windows 7 to sleep, the computer appears to sleep, but then it immediately wakes.
This problem may occur when you use the Start menu, a sleep button on a keyboard, or a Microsoft Windows Media Center remote control.
This problem occurs when you use the following two devices:
A USB device that supports the wake from sleep functionality of a keyboard, a mouse, or a 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 1 (Recommended)
Plug the USB device into an Enhanced Host Controller Interface (EHCI) host controller.
Disable the USB device's ability to wake the computer. To do this, follow these steps:
Click Start, right-click Computer, and then click Manage.
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.
Click Device Manager, expand Universal Serial Bus controllers, right-click the device, and then click Properties.
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 Workaround 1 because it preserves the wake functionality. When you use Workaround 2, USB devices cannot wake the computer. Additionally, the remote control power button for a Windows Media Center IR receiver cannot wake the computer.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
When the computer goes to sleep, USB devices turn off. The UHCI host controller interprets this event as if the USB devices were 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