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How to check hard drive configuration
Your hard drive is not working correctly, and you suspect that it may have lost its sector translation or that it may not have been installed correctly. Alternately, technical support recommends that you check the configuration of the hard drive.
Before resolving problems with a hard drive, it is often necessary to first determine whether the hard drive has been correctly configured. This will determine the appropriate steps for correcting any problems.
Note: Hard drive configuration is a broad topic; this document is only an introduction to the subject. For more complete information, see "More information" at the end of this document.
Please click the arrow to view detailed information on each topic.
What is hard drive configuration?
DOS can only recognize up to 1024 cylinders on any hard drive. All large hard drives (those with more than 528 MB of formatted disk space) have more than 1024 cylinders. Such drives require something to translate the real number of cylinders into a number that DOS can work with. This is called sector translation. A properly configured hard drive is either too small to require sector translation, or has sector translation correctly installed.
Why hard drive configuration is important
Sector translation is like a map that points to where the programs and data are on the hard drive. If the map is missing, or if it is not working correctly, information is written to the hard drive in the wrong places. This can overwrite other information, wiping out data that you have saved. In some circumstances, it can wipe out the system area of the hard disk, including the file allocation table (FAT). The FAT keeps track of where each piece of a file is saved. When the FAT is gone, the system may still have a record of the beginning location of a file, and the file length, but it will have no record of the location of the remaining pieces.
Which hard drives require sector translation
All hard drives with more than 1024 cylinders require sector translation. All drives larger than 600 MB require it, but very few drives under 500 MB do. Drives within the range of 500 to 600 MB may or may not require it; however, most drives as large as 528 MB and 540 MB do require sector translation. The best way to determine whether it is required for your hard drive is to check the hard drive's documentation for the number of cylinders.
Types of sector translation
Three components on the computer control sector translation: the CMOS, the hard drive controller, and the hard drive itself. Each of these components must be set in some way to identify which type of sector translation to use. Only one type of sector translation can be in use at any one time. Although each component is set for the particular type of translation to use, the translation is performed by one or more of these components:
- In the BIOS. The BIOS often uses Logical Block Addressing (LBA) to translate sectors, but it can also use other, non-LBA methods. To check this, refer to the computer's documentation. Turning LBA on or off in the BIOS after the hard drive has already been installed can cause sector translation problems.
- On the hard drive controller. All SCSI drives translate sectors with the hard drive controller. Many Enhanced IDE drives also have the capability to translate sectors with the controller. When the hard drive controller performs sector translation, the hard drive usually uses LBA.
- On the hard drive itself. Program files can perform sector translation. In this case, the computer needs to load the files on bootup. Sectors can also be translated with what is called an overlay. An overlay is information written to an area of the hard disk that is accessed automatically every time the computer is booted from the hard disk. Typical programs that do this include OnTrack's Disk Manager, and EZ Drive.
Determining whether the hard drive is configured correctly
On some computers, Windows 9x/Me will automatically translate sectors on the hard drive. However, if the hard disk has not been configured correctly, even with Windows 9x/Me installed, the sector translation will not work correctly when the computer has exited to MS-DOS mode or booted to MS-DOS mode.
Windows NT/2000 automatically translates sectors on the hard drive as long as the hardware on the system has been certified by Microsoft to be compatible with Windows NT/2000. The hardware most likely to affect compatibility issues are the hard drive, the hard drive controller, the system's motherboard, the CPU, and the BIOS. You can check your system's component compatibility in the Windows NT/2000 Hardware Compatibility List.
Hard drives that appear to be OK but are not
Regardless of whether sector translation is missing entirely or is there but not working correctly, the hard drive may appear to be working correctly. Problems will not manifest until information is saved to the cylinders with the wrong pointers, and cylinders above 1024. For these purposes, which program saved the information and what information was saved has no effect on the problem; the sector translator (or the lack of a sector translator) saved the information in the wrong place. Although this can happen when anything is saved to the hard drive, it happens more frequently in the following cases:
- You save a large file.
- The drive has about 500 MB to 600 MB in use.
- You run a defragmenting program such as Disk Defragmenter or Speed Disk.
- You run a utility program that uses the diagnostic cylinder or saves information at the end of the drive, such as Image.
- You run a hard disk repair program which is allowed to fix bad sectors, such as ScanDisk and Norton Disk Doctor.
Determining whether sector translation is working
There is more than one way to determine whether the sector translation is working correctly. Here are some ways that you can use with many computers:
When sector translation is not working
- Run the surface test in Norton Disk Doctor or a similar program, but do not allow it to fix anything. If sector translation is not working, when Disk Doctor passes the 1024th cylinder, it will say that all of the remaining sectors and clusters are bad. This will happen about 500 MB to 600 MB into the hard drive. If you are unable to get into the normal Windows 95 desktop, boot to DOS and run NDD.EXE from there. If you are not sure how to get to a DOS prompt, see the document How to get to DOS to resolve Norton Utilities problems.
- Run FDISK. This is a DOS utility program available on systems running DOS, Windows 3.x, and Windows 9x. It is not available in Windows NT. When running FDISK, do not change anything. Choose the option that displays the partition information. This lists all partitions on the drive. If the sum of the sizes of the partitions (listed as Mbytes) does not equal the total disk space listed, the hard disk is not configured correctly. Do this for each hard drive. To change drives, choose the option "Change current fixed disk drive." For further information on FDISK, see the sections beginning with Using FDISK to Check the Drive in the documents
Error: "Drive C: may not be configured properly" when running Norton Disk Doctor or Speed Disk.
"Drive C: may not be configured correctly" when running Disk Doctor or Speed Disk after installing Norton Personal Firewall 2002
- Boot up the computer, and read the messages on the screen as it boots. If you used to see a message that explained how to boot up from a diskette, but you no longer get that message, the computer may have lost its sector translation. The message will be similar to "In order to boot from floppy, press F1 now."
- Use the Norton Utilities Disk Editor program to look at the partition table and at the values that DOS sees. Disk Editor is not available for systems running Windows NT. See the article How to diagnose hard drive bootup problems with Disk Editor.
When the hard drive is not configured properly
If you know that sector translation is not working on a hard drive, back up all data you still have access to. If you do not have access to all your data, see the section later in this document about recovering data.
Fix the sector translation
Since sector translation is part of the hard drive installation, fixing the sector translation may require repartitioning and reformatting the hard drive. This will wipe out your data, so back it up before fixing the sector translation.
The method you use to fix the sector translation depends on which type of translation the hard disk uses. The user's manual for the computer or the hard drive should tell you the type. If it does not, you may need to contact the dealer, or contact technical support for the hard drive or computer.
Norton Utilities does not fix sector translation problems, but if you are unable to back up all your data, you may be able to use Norton Utilities' Disk Editor to retrieve some of the missing information. Do this before attempting to fix the sector translation, since that may involve wiping the hard drive. Disk Editor works on FAT12, FAT16, and FAT32 partitions, but it does not work on Windows NT NTFS partitions. Disk Editor is not available with Norton Utilities for Windows NT.
Disk Editor is an advanced program requiring knowledge of hard drives; not everyone may wish to invest the time necessary to learn enough about hard drives to use Disk Editor. Other methods of reconstructing your data may be quicker and easier. If you have no backups and no way of reconstructing your data from hard copy, you may be able to restore the data by using Disk Editor, or you may choose to send the hard drive to a data recovery service.
For step-by-step instructions on using Disk Editor to recover data, refer to these user manuals:
Here are several of the ways that hard drives lose sector translation:
- Norton Utilities 2001 for Windows 9x/Me/NT/2000, page 90.
- Norton Utilities 2000 for Windows 9x/Me/NT/2000, page 90.
- Norton Utilities for Windows 9x Version 4.0, page 83.
- Norton Utilities for Windows 9x Version 3.0, page 3-34.
- Norton Utilities for Windows 95 Version 2.0, page 6-34.
- Norton Utilities for Windows 95 Version 1.0, Appendix A, Scenario 16 (page A-25).
- Norton Utilities Version 8, Appendix B, pages B-22, B-27 and B-28.
- Norton SystemWorks 2001 for Windows 9x/Me/NT/2000, page 143.
- Norton SystemWorks 2000 for Windows 9x/Me/NT/2000, page 142.
- Norton SystemWorks 2.0 for Windows 9x, page 95.
- Norton SystemWorks 1.0 for Windows 9x, page 85.
How hard drives become improperly configured
- The hard drive is installed incorrectly. For a hard drive to be correctly installed, the BIOS, the hard drive controller, and the hard drive must all be configured to use the same type of sector translation. Here are some typical ways that hard drives are incorrectly installed:
- Two types of translation are being used for the same hard drive.
- The BIOS is set to use LBA for all drives, but one drive is using an overlay.
- The hard drive controller is using Logical Block Addressing (LBA), but the BIOS is not capable of LBA.
- A new hard drive was installed, but because the hard drive controller was not changed, the hard disk was not reformatted.
- A new hard drive controller was installed, but because it was the same type as before, the hard disk was not repartitioned. In most cases, the hard disk must be repartitioned even when using the same type of hard drive controller as before.
- Someone booted the computer incorrectly from a diskette, and then saved information to the hard drive. When using the type of sector translation that is on the hard drive, the computer must read sector translation information from either the hard drive before booting up from a diskette, or from the diskette. In the first case, wait for a message on bootup that says to insert the diskette before you actually insert the diskette. In the second case, the necessary files must be copied to the diskette before booting with that diskette. Documentation for the hard drive should give instructions for both these cases.
- The hard drive has physical damage in the system area of the hard disk. This can affect the Master Boot Record (MBR), Partition Table, or File Allocation Table (FAT). If Norton Disk Doctor reports a physical problem in one of these structures, you may need to replace the hard drive.
- The hard drive is infected with a virus that wiped out the sector translation files or the overlay (if applicable). This only applies when the hard drive is using the type of sector translation that is on the hard drive itself.
- Someone deleted the files necessary for sector translation. This only applies when the hard drive is using the type of sector translation that is on the hard drive itself.
- The hard drive is installed correctly, but the LBA setting in the BIOS was changed after installation.
Situations that resemble an incorrectly configured hard drive
- Master Boot Record (MBR) viruses can cause damage that does not wipe out the sector translation, but does move or wipe out the file allocation table (FAT), which makes information on a hard disk inaccessible.
- Programs that change the partition table on a hard drive are changing the MBR. An antivirus program will recognize that the MBR has changed. Since it may not be able to tell whether it was a legitimate change, it will ask whether you want to repair the MBR. If you tell it to repair the MBR, it will return the MBR to the way it was before changes were made to the partition table. This causes much or all of the information on the hard disk to be inaccessible.
Translations of this Document:
Given the time needed to translate documents into other languages, the translated versions of this document may vary in content if the English document was updated with new information during the translation process. The English document always contains the most up-to-date information.