That's where the problem lies, you cannot simply install your OS into
a computer with a new Mobo and CPU, unless same make and model,
without making modifications, prior to change over, as it is different hardware etc.
As the old Mobo and CPU are faulty, that poses issues, I would have suggested following this tutorial
but you will be unable to follow Steps 1 to 5
A new install may be the only way.
Also be aware that by changing your Motherboard your Windows licence may not be valid.