My old mobo is dying out and I ordered a new mobo, so do i need to reinstall windows 8.1 pro? Old one is M5a78l m le from asus and new one is Gigabyte Ga-78lmt-USB3. Old CPU was Athlon II X2 260 and New one is FX 6300 and new Gpu is Sapphire r7 260x. Btw OS is retail Win 8.1 Pro X64 and not OEM version/upgrade version.