Number 226 - March 2002

Recovering From Hard Drive Failure
by Brian K. Lewis, Ph.D.*
One of the most common problems that I run into is a failing or failed hard drive. All too often the owner has not been conscientious about keeping the data and programs backed up. I have seen situations where the computer is in Florida and the original application disks are somewhere up North. It is very difficult to restore programs if you don't have the original disks or don't have a complete backup. Any backup should include the Registry files, otherwise, you will have to reinstall all of your application software. Just keep that in mind as we go through some of the things you may have to do when your hard drive starts to give you error messages or simply won't boot into Windows or even into Safe Mode.     What types of error messages can you expect when your drive starts to fail? You may simply get a message that a file can't be found or it can't be loaded because it is damaged. Or, you may get a "sector not found" error message. The worst case may be when the computer tells you your hard drive is not bootable. In the first two cases, if you can still run Windows, try running Scandisk and use the "Thorough" setting to check the surface of the hard disk.     You may find that one or more sectors are bad and need to be marked so they can no longer be used for data storage. Scandisk will attempt to move the data to a safe location. If you can't run Windows in normal mode, but it will boot into safe mode, then you can still run Scandisk to check the drive condition.     For those who have never used Scandisk, you click the Start button and then select Run. The command to be typed in the run box is "Scandskw", without the quotes.     If you can no longer get Windows to run in either normal mode or Safe mode, then you need to use your Windows startup disk. You did, of course, make a startup disk when you installed Windows. If you haven't made one, do it now, before you need it. Go to the Control Panel, click "Add New Software" and in the next window, click on the Startup Disk tab. In Windows 98 this will prepare a disk with diagnostic software, including Scandisk. Now, when you boot with this floppy disk, you can run Scandisk and check the drive surface.     If you are still using Windows 95, then you can make a Startup disk the same way. However, it will not include all the files you need. Microsoft has provided software to help you recover from disk problems. The Emergency Recovery Utility (ERU) is part of the Windows 95 Resource Kit, but it is also provided on the Windows 95 CD-ROM. You can find it in the other\misc\eru folder. I suggest moving this to the backup folder in the windows folder on your hard drive. When you run the ERU, save the files on a floppy disk for the time when you will need it.     With either Win98 or Win95 you want to run Scandisk after you have booted your computer. If Scandisk repairs your drive so that you can again run Windows or your application, you are home free for the moment. However, in some instances you will need to replace damaged files. How you replace them depends in large part whether they were part of Windows or another software application. Those that belong to another application can probably be restored from your backup.     No backup? Then you will need to reinstall the application. Suppose, as can happen, the damaged files were in the Windows sub directory and you had to wipe out all the files in that particular location. That would include all the system files, the library files (DLL's) for many applications, hardware device drivers, etc. In this case, if you don't have a backup, you would have to reinstall Windows and all of your applications. Even if the application files weren't damaged, their reinstallation is necessary to place the necessary files in the Windows and System sub directories. This will also add the necessary references	to the application in the Registry. Believe me, having a complete, current backup can save you hours of work.     This discussion has assumed that the problem on the hard disk is relatively minor. Hard disks can develop small problems and continue functioning for long afterward. In other cases, once the surface starts to fail it rapidly becomes a progressive disease leading to total failure of the drive. If the damaged areas do not involve the boot sectors, you will have a little time to ensure that you have a current backup. If it involves the boot sectors, you will get a message telling you that the drive is not bootable or system files were not found-please insert a bootable disk. Now you need that Windows Startup disk.     Once you have booted from the Startup disk, then run Scandisk. To replace the system files you run the SYS program. The SYS program copies the IO.SYS, MSDOS.SYS and COMMAND.COM files to the hard drive. The first two have to be written to the system area of the hard drive, usually track zero. If this area is damaged, you will get an error message. The SYS program is automatically included on the Win98 startup. You may have to add it to your Win95 Startup disk.     If the Sys program doesn't successfully replace your boot file (system files), your next step is usually to replace the hard drive. You can try to correct the problem by reformatting the hard drive. However, in my experience, once the boot sectors are damaged, the drive is usually unusable as a primary drive. It can sometimes be used as a secondary drive providing the remaining surface is not damaged or failing. Scandisk can help you determine that.     In some cases, Scandisk will start reporting sector problems and the number of bad sectors will rapidly increase day by day. When this starts happening, you should be preparing to replace the hard drive. There are some utilities, such as "Lost & Found" that can help you recover files from a failing drive. However, they can't prevent the failure from continuing. So, this is just another reason for maintaining a regular system of backing up your drive.     How you back up your drive depends on how much effort you are willing to put into the recovery process. If you are willing to reinstall all of your application software, then you only need to back up your data files. If you have updated some applications with downloads from the Internet, then you may not want to reinstall the original application. In that case you need the downloaded file saved on some other media so it can be installed. The only other option is to have a full backup of your entire hard disk, including the registry files. You will still have to make the hard drive bootable, which may mean installing Windows again. Most backup software can't be run from DOS or a floppy. They will run only under Windows. After you reinstall Windows and start the restore process, you will receive messages that such and such a file can't be restored because it is in use. This refers to the library files and EXE files that Windows loads so it can run. Don't let that bother you, just continue the restore process. If your backup is recent enough, then your registry will be accurate enough that you won't have to restore your applications. Maintaining a current backup of your hard drive, or several recent backups, should be part of your routine maintenance of your computer system. It is, by far, the best tool to help you recover from a hard drive failure.     Copyright Sarasota PC Monitor, Sarasota Personal Computer Users Group, Inc.     *Dr. Lewis, a former university & medical school professor, is a computer consultant doing instruction, hardware/software services and system upgrades. He is available to help you with your home or business computer problems. He does make house calls and can be reached via e-mail at bklew@worldnet.att.net or voice mail at 941/925-3047.
Number 226 - March 2002