MCS? Or do you mean MSI which has LU6?
Go to your product site, download appropriate BIOS file from there and use MFlash which is much safer than BIOS update through OS.
My gaming 7 updates the bios through the live update fine.
I'm aware, I have had Gigabyte boards, but they all died on me (Not a good experience) But Msi has been flawless for me.