I just got the latest known version of the AMD K7 processor driver for Windows XP. This is version 5.1.2600.28 and it is WHQL certified. The file itself is dated February 12th 2002. The previous version from WindowsXP was 5.1.2600.10. Research in the .inf file showed reference to the knowledge base article Q306458 which basically deals with AMD PowerNow! support under Windows XP which only applies to mobile AMD CPUs. However this is the latest release and if you want to give it a try hit read more.

Note: Manual installation via device manager is required. Download