Hi Adrian, thanks for your answer!!
May I'm wrong, but there is talking about ALC1200 and I have ALC800, and also, the mother listed is a MSI P45 NEO3-FR and I have a MSI P45 NEO-F.
I followed the steps.
1. I removed the kexts, only I had AppleHDA.kext. So, I removed it doing: sudo rm -r...