If you see the “Operating System Not Found” message when starting your computer, follow these steps:

1. Power on the computer, and then repeatedly press the F2 key to enter the Setup Utility.

2. Press the left or right arrow key to highlight Main at the top.

3. Look for the “IDE Channel 0 Master” or “SATA Port 1” item. To the right of this item, you should see the model of the hard drive listed.