If you decide to install the SP3 and AMD processors and you have already installed but your system goes into a loop of continuous reboots the cause is in the Windows registry, which loads at startup drivers for the Intel platform.
This problem is evident especially for machine tools with preinstalled operating system ( HP ) where the initial image from the manufacturer was created on the Intel platform.
The solution is a small Visual Basic script, written by Jesper Johansson , this script checks to see if you have installed an AMD, and if so provides for verification and possible correction of the register.
Council to run the script BEFORE the upgrade, but if the problem has already been presented to start XP in safe mode (F8 key at boot) and run the script in this mode.
Source: Jesper's Blog
