Mmmmh, 2 laptops, bought at the same time, with diffrent OSes, both having the same problem? It might just be fate telling you to stay away from lenovo.
My stance, and Luis Villazon's (my troubleshooting mentor) is when a laptop starts acting up, it's best to buy a new one, or a second hand one from E-bay. this is because Computers are like old testament gods, lots of rules and no mercy. Troubleshooting a laptop is very dificult and it usualy boils down to - Change Ram - change the hard-disks - clean up dust from fans ---and failure to that, buy a new motherboard. The mobo costs as much as second hand lappy on e-bay.
So try those fixes but i'd advise buying laptops to save you a lot of valuable time and money.