Recently my Acer desktop broke and it will turn on but it won't boot, but the hard drives still spins so I suppose that it still works. If I was to build a new computer and I salvaged the hard drive from this old Acer desktop, would I be able to use the copy of Windows 7 from that is still on the hard drive? The computer didn't come with the Windows 7 disc but I have the product key on the case.