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"Missing Operating System" and "No ROM BASIC" Error Messages (80304)

The information in this article applies to:
    Microsoft MS-DOS operating system 3.1
    Microsoft MS-DOS operating system 3.2
    Microsoft MS-DOS operating system 3.21
    Microsoft MS-DOS operating system 3.3
    Microsoft MS-DOS operating system 3.3a
    Microsoft MS-DOS operating system 4.0
    Microsoft MS-DOS operating system 4.01
    Microsoft MS-DOS operating system 5.0
    Microsoft MS-DOS operating system 5.0a
    Microsoft MS-DOS operating system 6.0
    Microsoft MS-DOS operating system 6.2
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22
    Microsoft Windows 95

This article was previously published under Q80304


When you start your computer, you may receive one of the following error messages:
    Missing Operating System
    Non-system disk or disk error
    Boot error Press F1 to retry
    Invalid Media Type
    Hard Drive Controller Failure


Missing Operating System

This error occurs when the boot record signature of the master boot record does not match a certain value at a certain location. In this case, the boot sector is invalid and the computer cannot boot. This error can also occur if there is no active partition defined in the partition table.

Non-System Disk or Disk Error

This error is generated by the computer's BIOS when the boot sector or master boot record of the boot drive is damaged or missing. This error can also occur if the boot device has been improperly configured in the BIOS. In this case, data in the partition may be valid and undamaged, but there is no bootable partition.

NOTE: This message also occurs when a non-bootable disk is left in drive A during startup. If you receive this error, make sure that there is no disk in drive A and restart your computer.

Boot Error Press F1 to Retry

This error is generated by the computer's BIOS when the hard disk is missing a master boot record or boot sector, or when there is a problem accessing the boot drive.


If there is no active partition defined, the master boot record returns an error to the BIOS. In some cases, the master boot code attempts to go to ROM Basic when no bootable disk is found. Since some computers do not have ROM Basic, they display a NO ROM BASIC or other error message. The message displayed is dependent upon the computer's BIOS.

Invalid Media Type

This error message is displayed when the boot sector of a defined partition is damaged. The error message is normally received using a new partition that has not been formatted. However, if the boot sector is damaged, the partition may appear unformatted to the operating system, and this error message is generated.

Hard Disk Controller Failure

This error message indicates either the hard disk controller has failed, the hard disk controller is not set up properly in the BIOS, or the controller cannot communicate with the attached drive(s). In this case, do not perform the troubleshooting steps below. Instead, consult the documentation included with your computer or contact the computer's manufacturer for more information.


Each of the error messages listed above may indicate problems ranging from improper hardware configuration to damaged hard disk partition information. The following steps can be used to help resolve the problem. However, if these steps do not resolve the problem, please contact your hardware manufacturer or have the drive serviced by a qualified service professional.

    Start the computer using the Windows 95 emergency boot disk (EBD) or using a bootable MS-DOS disk that contains Fdisk.exe,,, and Scandisk.exe (MS-DOS versions 6.2x only).

    If your computer does not start from drive A, or if you receive an error message similar to one listed above when you start from drive A, please contact the computer's manufacturer.
    Use Fdisk.exe to view the partitions on the hard disk by performing the following steps:

      Run Fdisk.exe from the EBD or bootable MS-DOS disk.

      NOTE: If the hard disk was not partitioned using Fdisk.exe, use the appropriate third-party partitioning software to view the hard disk partition(s). For instructions on using the third-party partitioning software, please consult the software's documentation.
      Select option 4 (Display partition information).
      If the partitions are listed, make sure that the bootable partition is defined as active (look for an uppercase A in the Status column.)
      If there are no partitions listed, use Fdisk.exe to establish new partitions and then use to format the partition you want to boot from.

      WARNING: When you use Fdisk.exe or to create new partitions or format the drive, you lose any data on that drive or partition.
      If all the partitions appear in Fdisk.exe, and one is defined as active, proceed to the next step.

    Run the SYS command on the hard disk from the EBD or bootable MS-DOS disk. For example, type the following command:

    a:\sys c:

    If you receive the message "System Transferred," remove the disk from drive A and restart the computer. If you receive the same error message after you restart your computer, your hard disk may be configured improperly or damaged.

    If you do not receive the "System Transferred" message, or if you receive an error message, run ScanDisk from the EBD or bootable MS-DOS disk (MS-DOS version 6.20 or later) to check for physical damage on the hard disk by typing the following command:

    a:\scandisk c:

    If you are prompted to perform a surface scan, choose Yes. If ScanDisk reports physical damage on the hard disk, have the hard disk checked by a qualified service professional.

Modification Type: Major Last Reviewed: 5/12/2003
Keywords: kbDiskMemory kbScanDisk KB80304