Windows XP SP2 Laptop Battery Drain patch (KB918005)
Posted on Friday, May 19 2006 @ 11:31:35 CEST by LSDsmurf
When you unplug the AC power from a Microsoft Windows XP-based portable
computer, the battery may drain more quickly than you expect. Therefore,
the operating system may shut down prematurely.
This problem may occur if one of the following conditions is true:
The portable computer cannot enter the deeper Advanced Configuration and
Power Interface (ACPI) processor idle sleep states.
This occurs when the USB 2.0 driver leaves the asynchronous scheduler
component running continuously. This prevents the processor from entering
the deeper ACPI processor idle sleep states, or C-states. C-states save
power when the processor is not busy. These states range from C0 to C3 or
C4. Typically, an idle portable computer uses the C3 and C4 states to
preserve battery power. If an idle portable computer cannot enter or
maintain the C3 or C4 states, the battery power drains more quickly. This
problem is fixed by installing the download that is available in this
The USB host controller is unable to turn off.
This typically occurs when devices are removed from a nested USB hub that
is attached to the host controller. The host controller does not recognize
the device removal. Therefore, the controller is never turned off. This
prevents the processor from entering the ACPI processor idle sleep states.
This problem is not fixed by installing the download that is available in
The USB host controller uses the periodic scheduler for USB 2.0 devices.
This typically occurs when devices that rely on the periodic scheduler are
attached to the host controller. These may be isochronous (Isoch) devices
such as audio devices. Alternatively, they may be interrupt devices such
as mouse or keyboard. This problem is not fixed by installing the download
that is available in this article.
Program Information Category:
Tools and Utilities Type:
Free Version: (KB918005) Size: 570KB Works on: Windows