Don writes in with a hardware question
Q. I have a PC with the following specs: processor:AMD 64 X2 4000+ : 2.1GHz RAM :1GB ,DDR2 motherboard:ASUS M2N-MX SE OS :Windows XP SP2. The problem is my OS is not detecting my dualcore procssor,its working as a single. I found this when I tried to get the CPU usage graphs for both cores from Task Manager And in Device Manager. It is written as ACPI-PC (which I guess is for single core) from net i found that for dual core its will be another (forgot the name) How can i make my OS to detect my dual core or is it a BIOS setting problem?
Answer: Have you tried to update the driver by right clicking on ACPI under computer? Make sure to choose Install from a list or specified location (Advanced). Then choose Don't search. I will choose the driver to install from the next screen. Then choose ACPI Multiprocessor PC from the list.
If ACPI Multiprocessor PC is not an option when you update the driver then it could be something in your BIOS that is not correct. I would check there to see what your BOIS thinks your processor is.