 The magazine of the Melbourne PC User Group The DOS Doctor A Lucky Escape |
Computer problems today are more likely to be caused by software than by hardware. One seemingly small but careless alteration to a setting or deletion of a file can cause major problems and may even stop your computer from functioning. Hardware can still fail, but usually this is within the first few weeks or months of the computer's life span and should be fully covered by the manufacturer's warranty.
The most common hardware item to fail is the hard disk drive, next is the monitor. With the exception of the new LCD monitor panels that are starting to come onto the consumer market, very little has changed in monitor technology during the last 10 years. Monitors still consume most of the power used by the computer and certainly generate most of the heat. It's the heat and subsequent cooling when turned off, thermal shock, that causes monitor faults, just as it does with many other electronic devices.
On the other hand, hard disk drives (HDDs) have become much larger in capacity, faster in data transfer speed and lower in price. Reliability is still an issue and from time to time problems occur. There are only three or four major HDD manufacturers and the same makes and models of HDD found in brand name computers can also be found in the clone models. HDD failure can represent a major disaster to the user if valuable data is subsequently lost. It makes no difference how much you paid for the computer or from where you purchased it, failure can happen to anyone at any time.
I relate a recent experience with a client who had used the computer as a general workhorse, partly private, partly business. Backups were not something this client had ever considered a real necessity because, initially, there was nothing of any importance. Over time, however, valuable and to some extent irreplaceable information was stored on the computer. I received a desperate phone call early one morning, please can you come ASAP to look at this problem. The computer would not start correctly and they needed to extract some extremely important data. As it happened I had planned a morning in the workshop and was free to attend.
They had a Pentium 166 that was about five years old. There are many of this type of PC still in use today and for word processing, accounting, Internet and the like, they provide adequate performance.
No Hard Disk Drive
When the computer was turned on the startup BIOS messages appeared quite normally and displayed the setup data. Now, usually this is followed by the HDD manufacturers name and HDD size which is either automatically detected each time (ie. read directly from the disk at startup), or simply redisplayed (from internal memory), depending on the CMOS setup.
This was not to be the case. About 30 seconds ticked slowly by and finally the screen displayed that fatal message that no computer user ever wants to see. "Hard Disk Fail". I turned off the power and opened the case to physically examine the HDD and ensure the data cable was plugged securely into both the Main Board and the HDD. In situations like this it's a good idea to remove and reseat both ends of the cable to ensure a good connection. With the covers now removed I restarted the computer and listened carefully to the HDD as the power came on. There was no evidence of any movement whatsoever.
Normally you can hear the HDD spin up to full rotational speed and if you are holding it in your hand you may feel the slight centrifugal force caused by the spinning platters within. I commented that it appeared the HDD was dead. The response astounded me.
Warning Signs Ignored
Apparently for some time it had been necessary to turn the computer on and off several times, to get it to boot up properly. Why this was not taken as a sign of serious impending problems is beyond me. This is something about computer users I always find surprising. Failure to act upon the warning signs resulted in the real possibility that all data was now un-retrievable.
No Joy
A few attempts at powering the computer on and off produced no joy. Not having a suitable new HDD with me I suggested taking the computer back to the workshop to replace the drive with a new one and reload the main operating system (OS) and other things like the Internet connection. I asked my client for all the CD-ROMs and diskettes that belonged to the computer. With them I would have on hand all the programs required for a complete software rebuild and when I returned the unit it would be fully functional with correct driver software loaded for devices such as the Modem, Sound and Video Card and so on.
What I hadn't discussed with the client at this stage was the fact that probably the smallest available HDD (10 Gigabytes) would be larger than the computer's BIOS could recognise. Also, their version of Microsoft Windows was the original Windows 95, and this wouldn't recognise HDDs larger than 2.1 Gigabytes. As HDD sizes grew rapidly in recent years a later version of Windows 95 was released, Version B which addressed this and other issues. If you still use the original Windows 95 first release, you are somewhat restricted.
Some Luck Initially
In the workshop we got lucky. When I powered up the computer the HDD spun up to speed and was recognised by the BIOS on the first attempt. All the programs I tried at that point seemed to work okay, so I took the opportunity to run SCANDISK on the HDD to correct any FAT (File Allocation Table) errors. As the HDD was again working, although temporarily, I intended to use a handy utility program named GHOST, (published by Symantec) to clone the old HDD onto the new one. This would certainly save much time and retain all the clients programs and data. GHOST dislikes any corrupted data and although you can tell it to ignore such errors, I have found that it's much better to check and repair any errors before attempting a cloning session.
Risky Operation
In order to install a new HDD one needs to turn off the computer's power to make the required connections. Now this was potentially a risky operation - would it spin up yet again? I removed the old drive from its drive bay and replaced it with the new one. The old drive still needed to be temporarily available so I connected it with a spare ribbon cable to the secondary IDE controller. This avoided any potential master/slave conflicts that can occur when you have more than one device on the same controller.
Using a boot diskette containing a copy of essential programs such as FORMAT.COM, FDISK.EXE and GHOST.EXE I started the computer. When the enter setup message appeared I used the delete key to get into the CMOS setup, because the settings for the two HDDs had to be adjusted. This computer had an "IDE HDD Auto Detection" option so I was able to get the BIOS to detect the new drive, but, there was no detection of the old drive. As luck would have it the old drive again refused to spin up to speed.
I tried restarting a few times but to no avail.
A "Real" Twist of Luck
Finally in desperation I gave the old drive a sharp twist in my hand as I powered up the computer. Success!
It came up to speed and was detected.
The boot sequence also needed to be changed as it was previously set to start up on drive C: followed by A: rather than A: followed by C:. At this point the new HDD was useless as it was not partitioned, not formatted and didn't contain any operating system; so I needed the computer to boot from that special floppy in the A: drive.
With the computer now booted to the A: prompt and using the Microsoft program FDISK.EXE, I was able to partition the HDD. This program must not be used after data is present unless the user fully understands its operation because all data can be destroyed.
Software Limitations
Normally a new HDD is just partitioned into one large drive but since the original version of Windows 95 was to be installed, with its drive size limitation of 2.1GB, the drive needed to be partitioned into a series of logical drives, each 2.1 GB. A further complication was the older BIOS in this machine; it would be unable to recognise the 10.0 GB drive as being anything larger than 8.1 GB.
This is a limitation of these older BIOS however in my experience, apart from the inability to access some of the available storage space, they perform perfectly. When the HDD is installed later into a newer computer its full size will be recognised and the unused space can then be used.
With the new drive present at just over 8 GB, I simply created four partitions of approximately 2 GB using FDISK.EXE. The new drive letters were then C: through to F: with the CD-ROM drive now assuming the drive letter G:. Each drive was then formatted and using the GHOST program, which runs from DOS, I was able to copy the entire contents of the old 850 MB HDD to the first of the new 2.1 GB partitions, ie. the new C: drive.
Once GHOST had finished I removed the old drive, and its entry in the CMOS which allowed the computer to start up successfully without a hiccup.
Only one problem remained. Under the old setup with one hard drive (C:), the CD-ROM drive then had the letter D. Now it was drive G:. This meant than any installed programs, particularly Encyclopedias, Games, CD-ROM based Maps etc would all be looking at the new hard drive (D:) rather than the CD-ROM, to find their respective databases. There are commercial programs that will scan the Windows Registry and other locations to correct this error, however, I quickly used REGEDIT.EXE to locate any registry entries with reference to D: and simply altered them to G: (the old CD-ROM location to the new one).
This client was very lucky, they retained all their data and programs. However, considering they had no backups of their data they could have been in a real mess. Other clients have not been so lucky lately. The more common HDD failure is breakdown of the magnetic media in some areas making data irretrievable.
How good are your backups?
The Doctor may be contacted for comments and suggestions via e-mail to dosdoctor@wordpainters.com. We do not guarantee that all correspondence will be answered.
Reprinted from the September 2001 issue of PC Update, the magazine of Melbourne PC User Group, Australia
