This is an interesting exercise and there is a wealth of good and varied advice here.
However, standing back a bit, I can't help but think what an absolute mess the world of computing has got itself into. What should be a straight forward path is a journey riddled with pitfalls.
The answers to this problem should be just to buy the latest MS OS, insert disc and upgrade. Of course that could not be further form the solution. It is all a royal mess and an utter outrage.