I left my laptop, model Tecra S1, Toshiba, on for around three days and after I hear this buzzing sound at bottom left of my laptop. After the computer freezes so I turned it off and i decided to cool it off for 20 min. 20 min passed and I turned on the computer and it wouldn't boot unless if I used "Secondary Hard Drive" in the booting menu. So, I tried using recovery CDs but I noticed that it took a while to recover (around 3 more times slower than usual). After the recovery, I tried to turn it on but the message, "please insert bootable cd," or something like that over and over. If I try to go to primary or secondary hard drive options from the booting menu, it says error has occured please press ctrl+alt+del to restart computer. Thank you for the support. Does anyone know what is located inside the bottom left of the laptop, Tecra S1? I'm guessing it is the hard drive seeing how it makes a buzzing sound (like when a disk spins but it's getting scratched) and the laptop won't let me install anything on it.