AdamBruv :
Why would it need to be replaced?
Well depending on what you want to do, say gaming, the CPU is not very good, the RAM isn't enough, and to replace both of those you would need to replace the motherboard. At that point you will have replaced 80% of the system, including the GPU, and since the MB is already bare-boned it would be pretty difficult to find a replacement anyways.
But like I said it depends on what you are trying to do.