Questions
Q1
Why my system boot into Windows XP and get a blue screen of death then the machine reboots itself after install a new motherboard?

This is because of Windows SID protection. Windows will fail to boot and lock system due to the hardware ID changed. You will need to re-install the Windows XP after major componts upgrade, such like motherboard upgrade. Please back up all your important data with old motherboard and devices before install the OS again.