I have got an IBM M55 which is running on Windows XP and on it there is an intel core 2 duo as well. I installed CPU-z on it and it is reporting that 1 core is disabled and when I checked in Task Manager then I was only seeing 1 cpu. When I go into device manager then it reports that my computer is an "Advanced Configuration and Power Interface (ACPI) PC", so can you tell me how to change this from the current setting to "ACPI Multiprocessor PC", without reinstalling Windows XP? I have tried to update the driver but even after that I am getting "Advanced Configuration and Power Interface (ACPI) PC" and "Standard PC". Any ideas?