By default, Windows XP and Windows XP Service Pack 1 (SP1) do not enable AMD PowerNow! technology for AMD PowerNow!-capable AMD Athlon and AMD Duron processors. To enable AMD PowerNow!, you must install the latest processor driver from Windows Update.
Note The necessary driver support for PowerNow! technology is already configured on most systems sold by original equipment manufacturers (OEMs).
If you are using an AMD PowerNow!-enabled system and you reinstall Windows XP, you must download the latest Microsoft Processor driver from Windows Update to enable AMD PowerNow!. The default Processor driver (Processr.sys) installed with Windows XP does not enable AMD PowerNow!. If you experience symptoms such as decreased battery life or increased processor temperatures, this may indicate that you must update the Processor driver on the system. Also note that when you install SP1 for Windows XP, this does not switch the Processor drivers even though there is an updated driver in the service pack.
At the time that this article was written, the following is the latest Processor driver in Windows Update:
Microsoft Processor Driver Version 5.1.2600.1152
To obtain the latest Processor driver, use the Scan for Updates feature in Windows Update. The Processor driver is listed in the Drivers Updates section after the scan is completed.
The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products. Note If you use Windows Vista, you can visit the following Microsoft Web page for help with power consumption and battery life problems: