ROM BIOS Messages Indicating Boot Failure

With no valid MBR or bootable device found, systems with a very old IBM BIOS display the infamous ROM BASIC interpreter, which looks like this:

The IBM Personal Computer Basic Version C1.10 Copyright IBM Corp 1981 62940 Bytes free Ok

With no valid MBR or bootable device found, systems with an AMI BIOS display the following message:


This message is confusing to some because it seems to point to a problem with ROM BASIC, which of course is not what it really means!

The AMI ROM does not include a BASIC interpreter in the ROM (neither do any other ROMs except those found in very old IBM machines), so instead of jumping into BASIC or displaying a useful message indicating there are no bootable devices, it displays this confusing message.

The real meaning is the same as for all these messages, which is to say that none of the bootable devices in the boot sequence were found to contain signature bytes indicating a valid MBR in their first physical sectors.

With no valid MBR or bootable device found, systems with a Compaq BIOS display the following message:

Non-System disk or disk error replace and strike any key when ready

This is another confusing message because this very same (or similar) error message is contained in the DOS/Windows 9X/Me VBR and normally is displayed if the system files are missing or corrupted.

So, if you see this message on a Compaq system, you can't be sure whether the problem is in the MBR, VBR, or the system files, which makes tracking down and solving the problem more difficult.

With no valid MBR or bootable device found, systems with an Award BIOS display the following message:


So far, that appears to be the least confusing of these messages. You don't need a secret decoder ring to figure out what it is really trying to say.

With no valid MBR or bootable device found, systems with a Phoenix BIOS display either this message:

No boot device available - strike F1 to retry boot, F2 for setup utility

or this one:

No boot sector on fixed disk - strike F1 to retry boot, F2 for setup utility

Which of these two messages you see depends on whether no boot devices were found or readable, or a boot sector could be read but was found not to have the proper signature bytes.

Although the message displayed varies from BIOS to BIOS, the causes are the same for all of them. Several things can cause these messages to be displayed, and many of them relate to the MBR.

The primary causes are disks that are new (have never been partitioned) or that have had the MBR corrupted.

The MBR, including the signature bytes, is written to the hard disk by the FDISK, DISKPART, or Disk Management program. When a drive is new or freshly low-level formatted, all the sectors are initialized with a default pattern of bytes.

At that point, the first sector contains a test pattern or all 0s and the last two bytes of the sector do not contain the 55AAh signature. In other words, these ROM error messages are exactly what you see if you attempt to boot from a new hard disk or one that has been low-level formatted but not yet partitioned.

Now consider another situation that can cause these messages. If the signature bytes are correct, the BIOS executes the MBR code, which performs a test of the Boot Indicator bytes in each of the four partition table entries. These bytes are at offset 446 (1BEh), 462 (1CEh), 478 (1DEh), and 494 (1EEh), respectively.

They are used to indicate which of the four possible primary partition table entries contains an active (bootable) partition. A value of 80h at any of these byte offsets indicates that the particular table contains the active partition, whereas all other values must be 00h.

If more than one of these bytes is 80h (indicating multiple active partitions), or any of the byte values is anything other than 80h or 00h, you see the following error message:

Invalid partition table

If all these four boot indicator bytes are 00h—which indicates that no active (bootable) partitions exist—then the MBR returns control to the motherboard ROM. Also, if no other bootable devices exist, interrupt 18h is called and displays the same error messages as listed earlier.

This is exactly what occurs if you were to remove the existing partitions from a drive but had not created new partitions on the drive, or if you had failed to make one of the partitions Active (bootable) during partitioning before rebooting your system.

Another cause for these errors can occur with hard disks that are 8.4GB in size or less, which run in CHS mode. The problem is caused by tampering with the translation mode in the system BIOS for drives less than 8.4GB in size.

Translation is used by drives between 528MB and 8.4GB, which alters the reported CHS geometry of the drive into a format that enables the entire disk (up to 8.4GB) to be used by DOS and Windows. Typically, three settings exist for translation: It can be disabled (often indicated by a setting of normal) or enabled using either CHS or LBA values.

Translation using CHS values is often indicated by a setting of large, and translation using LBA values is indicated by a setting of LBA.

If a drive is partitioned and formatted with LBA translation and the setting is later changed to CHS (often indicated as large), the bootstrap loader in the BIOS translates drive sector locations differently and might not properly load the MBR or make the proper jump from the MBR to the VBR of the bootable volume.

This can cause one of the previously discussed error messages to appear, or it can cause the MBR to display the following message:

Missing operating system

Thus, if you see such errors on a system with a hard drive between 528MB (504MiB) and 8.4GB (7.9GiB), be sure to check the translation settings for the drive.

On some of the older AMI BIOS Hi-Flex and WinBIOS (graphical) versions, the translation mode setting is not on the same screen as the hard disk setup but is buried in the Advanced or Built-in Peripherals setup screens where it can be turned off by autoconfiguring BIOS setup options.