Hi all, im upgradeing my mb and cpu, at mo i have gigerbyte fm2 mb with amd athlon x4. im changeing to g1 sniper z87 and i7 1150 cpu, so i can sli gtx770, ive been told i have to format my hdd and reinstall windows 8, do i have to do this, couldn't i just uninstall all old Mb drivers, change hardware then reboot and install new drivers. if i have to format, how do u format the hdd your useing for os, because format is greyed out, do i have to boot windows from disc to do this, if so how? Im a noob to pc but im getting their with your help. The company where i bought the pc said because im moving from gigerbyte to gigerbyte mb and i have windows 8.1 theirs no need to do fresh reinstall, because windows 8.1 has some sort of thing that sorts hardware change out, but im thinking the cpu upgrade is a big one, athlonx4 to i7 4th gen. i only have photos to copy if i have to format so ill do that to flash drive, i have windows disc full version and key code so no prob their. thankyou i seem to be getting different answers so any advice would be much thanked,