You would have a limit on the hard drive size due to the old motherboard. The type of memory for such an old motherboard may not even be available anymore other than either second hand or comp fairs. If you change the motherboard you will probably find the new board will not fit in your case. You would have the same problem finding a processor as the memory. Might be better to cut your losses and buy new or put up with a slow computer and not expect too much of it.