A while back I re installed Windows 8.1 and it created a dual boot drive of Windows 8 and 8.1(except it would give me an error whenever I tried to launch 8). Well I upgraded to Windows 10 for free and would like to re install it to get rid of this secondary OS that doesn't even work. When re installing can I use my windows 8 Disc and key and still get Windows 10 since the upgrade is attached to my microsoft account?