AMD PowerNow! Functionality May Require a Driver for AMD Mobile Athlon 4 and Duron Processors with Windows XP

Support for Windows XP has ended

Microsoft ended support for Windows XP on April 8, 2014. This change has affected your software updates and security options. Learn what this means for you and how to stay protected.

This article was previously published under Q306458
This article has been archived. It is offered "as is" and will no longer be updated.
Advanced Micro Devices (AMD) offers PowerNow! technology on AMD mobile Athlon 4 and mobile Duron processors. The PowerNow! technology adjusts the processor's performance and power consumption by dynamically adjusting the processor's operating frequency and voltage. Windows XP requires an additional driver (the Amdk7.sys driver) to enable the AMD PowerNow! functionality. Laptop computers that are based on these mobile AMD processors and are shipped with Windows XP installed by the manufacturer are likely to have this driver already installed. If you reinstall Windows XP, you must also install the Amdk7.sys driver to use the PowerNow! technology.
The Amdk7.sys driver is necessary to enable Windows XP support for AMD PowerNow! technology on computers that use a mobile Athlon 4 or mobile Duron processor.
To resolve this problem, obtain the latest service pack for Windows XP. For additional information, click the following article number to view the article in theMicrosoft Knowledge Base:
322389 How to Obtain the Latest Windows XP Service Pack
The following file is available for download from the Microsoft Download Center:
Release Date: October 17, 2001

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.The English version of this fix should have the following file attributes or later:
   Date         Time   Version      Size    File name   --------------------------------------------------   29-Aug-2001  15:57  5.1.2600.10  32,768  Amdk7.sys   29-Aug-2001  16:19                1,562  K7qfe.inf				

To Install the Driver

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows

To install the and configure the driver:
  1. Click Start, click Control Panel, click Performance and Maintenance, and then click System.
  2. On the Hardware tab, click Device Manager.
  3. Double-click the Processors branch to expand it, right-click your processor, and then click Update Driver.
  4. Click Install from a list or specified location, and then click Next.
  5. Click Don't search. I will choose the driver to install, and then click Next.
  6. Click Have Disk, select the folder in which you extracted the Amdk7.sys and K7qfe.inf files, and then click OK.
  7. The AMD K7 Processor driver is listed. Click Next.
  8. Click Finish, and then click OK.
  9. Do not restart the computer.
  10. Start Registry Editor (Regedit.exe).
  11. Locate and click the following key in the registry:
  12. On the Edit menu, point to New, click Dword Value, and then add the following registry value:
    Value name: HackFlags
    Radix: Hexadecimal
    Value data: 1
    A value of 1 enables the legacy PowerNow! interface. To disable this feature, set the data value to 0.

  13. Quit Registry Editor.
  14. Restart the computer.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows XP Service Pack 1.
The new Amdk7.sys driver for Windows XP is also available from the Microsoft Windows Update Web site. If you install the driver from the Windows Update Web site, the driver is installed and configured automatically on computers that support the use of the driver.

Article ID: 306458 - Last Review: 12/06/2015 04:59:54 - Revision: 2.7

Microsoft Windows XP Home Edition, Microsoft Windows XP Professional

  • kbnosurvey kbarchive atdownload kbqfe kbenv kbdriver kbbug kbfix kbsetup kbwinxpsp1fix KB306458