This story is often because the machine was a Dell, HP or other make and the motherboard is not from that maker.
The XP CD is only for that make system so the installer may actually claim the motherboard is missing.
Tell more so a good answer can be had.
Hi, we just replaced the memory, CPU, and motherboard but Windows XP will refuse to install because it thinks that the motherboard is not physically there. However, we need to keep the data and applications intact so we can access them after the install. How do I do it? Please help!!