Okay so I have a Toshiba Satellite C55-A and I have a problem. I was on it the other day and it was working fine till all of a sudden the computer froze and all I did was turn it off. When I turned it back on it stayed at the "Toshiba leading innovations" screen for a minute and then it would go to a black screen and in the top left corner it would say "checking media. Media [failed]" i don't know what that means. Then a couple seconds after it would say "No bootable device -- please restart system" I don't know what to do and I need help, it would be well appreciated!