So i have 2 hard drives and they were both bootable. The computer stopped booting from the primary drive that i normally boot from (the 2TB) and instead started booting from the 500gb drive again. I looked in the bios the 2TB drive is no longer even an option to boot from. What the heck happened? -Both drives appear in the bios -Only the 500gb drive appears to be bootable -The 2TB HD was booting just fine until i came to visit my parents and found it was booting off the 500gb (everything was old and not updated) -The 2TB drive can be seen from the windows of the 500gb drive. I don't suppose there would be a quick fix for this? I'm having trouble finding information on google because it's mostly just entry after entry of drives not being visible in windows.