Installing Microsoft Windows XP Service Pack 2 on a PC with a "Prescott" CPU and certain chip sets can cause it to fail to reboot completely. The problem can be solved with a workaround or a BIOS update.
Depending on the chipset, motherboard manufacturer, BIOS version, and CPU, installing Microsoft Windows XP Service Pack 2 can result in an unbootable computer system. The problem is generally associated with Intel "Prescott" CPUs and its chipsets, but not every such combination will cause a problem. As of this writing, motherboards exhibiting the behavior include:
- Albatron PX865 PE Pro
- Shuttle SB61G2
- Jetway i875P
- Soyo P4I865P
- Aopen AX4SG Max
- Asus P4P800-E deluxe
- Abit IS7-V
- Foxconn 865A01-G-6EKRS
If the Intel utility shows that you have the wrong microcode version, the primary solution to the problem is to update the system BIOS for your motherboard before you install SP2. Here are some motherboard manufacturer links:
BIOS updates can be dangerous please follow the manufacturer's instructions very closely to avoid a major catastrophe.
If you have already installed XP SP2 and have a PC that will not boot because of this microcode version problem, there are two workarounds you can try to get to a bootable state.
In the BIOS setup you should temporarily disable the L1 and L2 cache. On some motherboards, this will allow the computer to boot. You should then remove SP2, turn the L1 and L2 cache back on, and then update the BIOS to reflect the correct microcode version. After completing these steps, you should be able to re-install SP2 without running into this particular problem again.
If disabling L1 and L2 cache does not work, you can use a second workaround suggested by a representative at Intel: Boot the problem computer with an alternative OS or to the safe mode command line if possible. Assuming you can get to the Windows directory on the boot partition, navigate to this file and change its name so that it does not load the next time the machine is booted:
After rebooting you should be able to install XP SP2, but keep in mind this is a temporary fix - the system will be unstable until you update the BIOS and reactivate the update.sys file.
Take care if you have to do anything with this.