Guys, this is very serious to me. I tried to fix the "missing operating system" problem by resetting BIOS settings to factory defaults with F9. I then pressed F10 to save and exit and rebooted the computer. The problem still exists. I then went to BIOS and enabled "OS Optimized Defaults', saved and exited BIOS. I rebooted the computer and nothing is showing. The monitor is not showing anything. I tried unplugging and plugging back the monitor cord but nothing happened. The CPU's LED is lit, which means it is turned on, but no results. I tried to reset BIOS with another way by taking out the CMOS battery for a few minutes and putting it back but nothing happened again. Please anyone help me. I don't have enough money to buy a new CPU so please guys.. I need help. CPU: Intel i5-3470 Graphics Card: AMD Radeon 6670 HD RAM: 10GB DDR3 Manufacturer: Lenovo I only remember these specs for the computer because I CANT EVEN TURN ON THE COMPUTER! Anyways, thanks!