Reference number: CH000181

Missing Operating System.

Issue:

Missing Operating System.

Cause:

Below is a listing of the different causes of the Missing Operating System error message.

1. Missing or corrupted command.com or other boot files.
2. Computer Virus
3. Boot Record is corrupted.
4. Hard drive has failed or has been erased.

Solution:

If you are receiving the Missing Operating System error message it is recommended that you follow the below steps to resolve the issue.

Caution: The below steps suggest using a bootable diskette, make sure this bootable diskette is designed for your operating system. For example, do not use a Window 98 bootable diskette and follow the below steps on a computer with Windows XP.

1. Using a write protected bootable diskette, boot from the diskette and type "sys c:" after pressing enter this should give you the message system transferred. Once this has been completed, reboot the computer. If you get any other messages, see our Boot disk page.
2. If the number one does not resolve your issue, boot from the diskette again and at the prompt type "fdisk /mbr" and press enter. This should just return you back to the prompt. Once back at the prompt, reboot the computer.
3. Finally, if one and two are unable to resolve your issue, it is recommended that you boot from the boot diskette again and reinstall or format and reinstall the operating system.

Additional information about formatting your computer and starting over can be found on document CH000186.