HP users have complained that XP machines powered by AMD processors have encountered problems once SP3 has been downloaded.
Users have seen their machine repeatedly boot up once they turn on their machines. The problem is caused by rogue code in the operating system which is designed for machines powered by Intel processors instead.
HP is said to have used the wrong version of the OS when loading XP on to machines in the factory.
Jesper Johansson, a former Microsoft security manager, has released a patch to fix the problem, ahead of both HP and Microsoft.
The free patch has not been sanctioned by either Microsoft or HP though, which are still working on a patch to help out their customers.
Johansson's small Visual Basic Scripting Edition file first checks whether the machine is running an AMD processor.
If it is, the software studies the Windows registry to see if the rogue device driver designed for Intel machines is about to be loaded.
If the driver is there, the user is given the option to disable, and avoid constant reboots of the machine.