Fix the error message Operating system not found

If when you boot your PC you receive the error message (Operating system not found), it's probably that Windows has lost partition information. Next, I will explain how to deal with 'Operating system not found'.

QUESTION: My PC's hard disk appears to have died. The machine is a few years old, but has been running fine and I haven't installed any new hardware or software. When I turn on the computer I get the message: ‘Operating system not found'.

I know a bit about PCs and Windows, and thought it could be a problem with the Master Boot Record. I booted from my Windows XP CD and used the Recovery Console to attempt to rebuild the OS. The plan was to use the fixmbr command, but I was stopped in my tracks when the Recovery Console reported that it couldn't find a hard disk.

Oddly, the Bios shows that the hard disk is still connected to the PC and it clearly has power. When I removed the case's side panel I can hear the disk whirring away as normal, with none of the ominous clicking sounds you might expect to hear from a failing drive.

I want to get the data back, but I can't afford to send my drive to a data-recovery firm.

ANSWER: From your description, it sounds as though your hard drive is okay. We suspect that the partition information may have been lost, however, which would explain why the Windows Recovery Console reports that no hard drive can be detected.

Even better news is that you may be able to solve the problem using a free recovery tool called TestDisk. It's a Linux tool but, as you can't boot into Windows, that's not a problem. Use another computer to download a Live distribution, which includes TestDisk. (Live distributions are Linux OSes that run directly off a CD or USB flash drive.)

One distribution you might like to try is KNOPPIX, which comes with TestDisk. Burn the ISO to a CD, or use a tool such as the Universal USB Installer to boot your PC.

Run TestDisk from a terminal window and follow the instructions provided.

Alternatively, connect your hard disk to a working PC and run the Windows version of TestDisk. It's the same command line tool, with little difference between its operation in Windows and Linux.