I need help installing Ubuntu on my Lenovo y50, I have Nvidia 2Gb GPU and 2GB integrated graphics. I also have a 1tb HDD hybrid with 8GB SSD. My question is how to install Ubuntu correctly on the HDD and utilize my dual GPUs like I do on windows so I use integrated for DE and automatically use Nvidia for resource demanding tasks like gaming. Also, I believe my OEM windows product me for 8.1 is built into my BIOS but I upgraded to windows 10. If I were to ever switch back with a windows 8.1 or 10 ISO would I be able to use this product key again?