I have a Lenovo laptop which I've recently replaced the failed hard drive. I want to make a bootable usb in order to load Windows 10 on the laptop new drive. Where would I find step by step directions for doing this? The laptop came with Windows 8 and was updated to 10 prior to failing. Do I have to go back to 8? I read somewhere that I'll need the Windows serial number that came with the laptop in order to install. Any help would be greatly appreciated.