My Win 10 became infected so I formatted my Samsung 850 Pro 256GB SSD and attempted to install Win 10. When I select format, I get '...this ide drive must be GPT'. I'm running a Gigabyte 990FXA-UD3 mainboard with an AMD FX8320 8-core CPU with a Corsair H80 cooler, 8GB Corsair Vengeance DDR3. I tried all the different settings in the BIOS: tried Legacy, UEFI, AHCI, nothing worked. This has always been a problem with this system. I have, in the past, been able to install 8.1 Pro and then upgrade. I've done it without issue several times. This time, Windows Update just sits there looking for updates. I have run several recommended Microsoft fixes ie: cmcd line entries. Ran the Windows Update fix, it found and fixed 3 errors. Any other kb files I download & attempt to install, they all look for updates. I reinstall 8.1 4 times now with no luck. When I run the Win 10 updater, it sticks at the same point as well. I've tried everything that I can think of. I work on computers everyday and have never run into this before. I plan on running MHDD on the 850 Pro and see what I get. Anyone have any good suggestions?