Hey everyone, i am about to upgrade my motherboard from a GA-M68MT-S2 3.1 to a GA-990FA-UD3 (and will be upgrading cpu to fx 8350) and i know that if i upgrade my mobo i will need to re install windows. I have windows 7 ultimate and would like to install windows 8.1 pro after the upgrade. How would i do this if i have no OS? Do i insert installation disc? Is there another way. Please help.