I have a HP ENVY dv7 that comes with two disk bays. Windows 8 has been installed in HDD1, and came with the laptop. I added another SATA HDD2 to the second disk bay and in it CentOS 6.4 was installed. I do NOT know how to boot from the HDD2, and there seems to be NO place for me to make changes in the BIOS to allow me to do that. Could someone out there tell me how I could do that?