There are several reasons why you might receive the “Operating System Not Found” error at start-up. It could be either software or hardware-related. While this will often spell disaster for most people, there are simple things you can do to fix the error without having to resort to costly repair shops or losing valuable data. Before you proceed, you will want to gather as much info about the computer as you can. What Operating System are you running, what model computer is it, what model hard drive is inside? Knowing these things will help you get the necessary tools to diagnose and repair the PC.
Check the BIOS Settings
If the hard drive is not configured properly via the jumpers or cables, you should be able to see this in the BIOS. You will want the drive with the Operating System to be the Primary Hard Drive. For troubleshooting purposes, you will also want the hard drive configuration set to AUTO and listed as the first Boot Device in the boot sequence section. If the hard drive does not show up, try changing the power connector and IDE (or SATA) cable. If the hard drive still does not show up, you will want to visit the hard drive manufacturer’s web site for their diagnostic tool.
Use The Recovery Console To Fix The Master Boot Record
If the drive shows up in BIOS, but you still receive the “Operating System Not Found” error, you might simply need to repair the master boot record. To do this, you will need an install disk or boot disk for your Operating System. When you boot to the disk, follow the prompts until you find the option for the Recovery Console. At the the console’s prompt, type fixmbr and hit return.
If running hard drive diagnostic tools from the manufacturer of your hard drive didn’t work, and it fixing the master boot record also failed, you may need to reinstall Windows. This will cause you to lose any data on the disk. As a final recourse, you can try plugging the drive in as Slave (if this is an IDE drive) on a working machine and see if you can browse through the files to save any data you do not have backed up. Attempt to reinstall when you are ready. If the disk still cannot be found, you could have a problem with the controller on the motherboard or the the drive itself may be defective.