I've been trying to upgrade my Plextor 256 GB M.2 NVMe with a Samsung 970 EVO 1TB on an MSI X99A SLI Plus. I'm trying to avoid all the installation and set up by cloning my old Windows 7 installation. I've tried the Samsung Migration utility and Macrium Reflect with the same result. Windows says it can't boot because the drive (boot media?) is unavailable. This happens after the windows animated logo, so it has to be reading the drive. I have updated to the latest BIOS, and tried to repair using the install CD.