Being a bit paranoid, I expect Hard drives to fail and I also do not expect OEMs to use top self components in budget applications. So.. since my current machine is 2 years old, I felt it was a good time to be proactive. I cloned the 2TB Seagate C: drive in my ASUS M51AC to a 2TB WD Black. All is well machine, boots up faster and responds a bit faster. The down side. The WD 2TB Black is noisy. So if anyone does live audio near their tower, the WD 2TB Black may not be a good choice.