Hard Disk: An Introduction

Hard Disks are used to store information. All information on computers are stored in files. Hard disks store the majority of information on today’s modern computer. Hard disk drives (HDDs) can be critically damaged by static electricity, shock, and other factors, often resulting in failure or the loss of valuable data. In many cases it may become necessary to recover information from your hard drive. Such retrieval is quite possible.

Hard Disk Failure

*Physical Failures

Physical failure occurs from sudden switch off, power failure, sliding them off desks and cheap components. As for data loss, data is only magnetic impulses on the surface of a hard disk. And ridiculously small bits of magnetism at that! When the magnetic impulse fades, or changes position, trouble starts.

Drive Alignment Drift is another cause of problems. Mechanical devices are subject to wear and tear, heat and cold, loosening tolerances etc.

The small changes in the read/write heads wouldn’t matter usually, as data still gets written in the same place as it will be read later. However, there is some data that hardly ever gets re-written, and that is the Sector ID Headers.

*Logical Failures

Master Boot Record Failure

Technically, when the Master Boot Record is working correctly, the master boot code scans the partition table for the active partition, finds the starting sector, loads a copy of the boot sector from the active partition into memory and then transfers control to the executable code in the boot sector. If the master boot code cannot complete these functions, the system displays a message similar to the MBR error.

*Boot Sector Failure

The boot sector is a region of a hard disk, floppy disk, and other similar data storage device. It is loaded to memory and executed as a part of the bootstrap sequence. The boot sector contains a small computer program that is loaded on the operating system into memory and transfers the control.

Most boot sector failure occurs by the defection of boot sector virus. Boot sector viruses are usually spread by infected floppy disks. In the past, these were usually bootable disks, but this is no longer the case. A floppy disk does not need to be bootable to transmit a boot virus. Any disk can cause infection if it is in the drive when the computer boots up or shuts down.

*Accidentally Deleted Data

Some time some how you may delete a file thinking we don?t need it any more, but in a week or or two you may realize that it is a needed one. It happens to the best of us, but fortunately there are ways to get these lost files back.

When it comes to data on your computer, it is almost impossible to accidentally remove it beyond recoverability. Even if you are intentionally trying to completely wipe a file from your hard drive it is exceedingly difficult.

*Cross Linked Files

A file system error that corrupts the contents of an existing file by writing data from another file into the same cluster. Running Scandisk or a similar program cleans up the problem, but one of the files is no longer usable.

*Bad Sectors

It is a portion of the Hard disk that cannot be used any more. If a part of the disk get bad sector which contains data then those data is to be recovered before use. When you format a disk, the OS will mark all the unusable sector as bad sector, however, this does not affect the overall performance of the disk as the damaged space is considered unusable.

Hard Disk Data Recovery

*Replace the (Circuit Board) PCB

Upon a Hard Drive circuit board failure, it is possible to get back the data by carefully replacing the PCB of the hard drive.

*Replace the Firmware

Hard disk firmware is the information that is used by the computer that allows it to correctly interact with the hard disk. It may be replaced or updated by the matching firmware.

*Replace the Head Stack

There are common situation that may be due to head failures. There is a small chip located in the head stack that is called PREAMPLIFIER. Working with preamplifiers always includes some difficulties, because, practically, they can not withstand static discharges. If re-soldering is needed, one should follow a number of rules to protect a preamplifier from static damage caused by careless finger touching. Although this task is very risky and it should be done in a high secured lab specially created for this task.

*Move the disk to another Drive

In some cases complete functionality of the Hard drive may be disabled while only the internal disk plate is without any damages or errors. In those situations, it is possible to move the disk to another drive.

*Spin-Stand Testers

Hard drive manufactures and their head media; preamplifier and read channel suppliers do have very accurate, very expensive “magic machines” called Spin-Stands. These are used for testing and experimenting with heads and disks. They are used mostly by researcher and development departments.

*Magnetic Force Microscopes (MFM)

Magnetic force microscopy is a powerful tool for high-resolution magnetic imaging of most data storage media. As the density of magnetic media is higher, the bit becomes smaller than the wavelength of light, so optical techniques can not resolve it. General MFM is capable of imaging the magnetic domain of several tens of nanometers. Also, MFM is almost simultaneous with measuring the surface characteristics of topography and roughness of the same area with sub-angstrom vertical resolution.

Recovery Softwares

*SpinRite 6.0

SpinRite is a stand-alone DOS program designed to refurbish hard drives, floppy disks and recover data from marginally or completely unreadable hard drives and floppy disks and from partitions and folders which have become unreadable.

*Ontrack data recovery software

Ontrack Data Recovery offers the industry’s highest quality and cost-effective do-it-yourself data recovery software solutions for almost any data loss situation covering servers, desktops or laptops for all media, operating systems and file types. Ontrack’s EasyRecoveryTM family of products is unmatched in its ability to recover/repair from all causes of lost data.

*Recover My Files

Recover My Files data recovery software will easily recover deleted files emptied from the Windows Recycle Bin, or lost due to the format or corruption of a hard drive, virus or Trojan infection, and unexpected system shutdown or software failure.

For more Data recovery topics http://www.pc4safe.com

About The Author
Admin & Publisher
PC4safe http://www.pc4safe.com

All file recovery solutions are not created equally. But, choosing one specific software or service company can be overwhelming from the sheer numbers available. For starters, why do some file recovery software cost as low as $29.99, while others range as much as $400? Before addressing these details, and how to choose the best file recovery solution for your situation, let’s make sure your files have the best chance to be recovered.

Safety First…

If you are reading this article on the computer you are trying to recover files from, do the following steps immediately (Your computer is always running in the background, and could be overwriting the data you are trying to recover):

1. Close any important documents that are open.

2. Print this article to follow off-line.

3. Unplug your computer (Do not turn off your computer, unplug it now.).

Note: Unplugging the computer stops the computer from running all together. Turning off or shutting down your computer might make the computer go through a process that could overwrite data – your files.

What not to do…

1. Do not run the system recovery disk from the computer manufacturer. This software is designed to get your computer running again with no regard to your data. In other words, it is not designed as a file recovery solution. Just ask the manufacturer if there is a possibility that you could lose data. Yes, is always the answer.

2. Do not install file recovery software on the computer you are trying to recover files from, for this could overwrite the files you are trying to recover. You must have a secondary storage device (i.e. hard disk drive, USB device, etc.) to install the program and to recover the files.

Note to Advanced Users: Even if you are trying to recover a particular partition, and already have a separate partition to install the file recovery software on, do not do it. Since there is possible corruption within the file system at this point, you run the risk of overwritting the partition and files you are trying to recover during the installation process. Better safe than sorry. Install the program on a secondary drive.

File Recovery Software…

Which file recovery software you choose depends on what has happened:

1. Have you accidentally delete a file that you want back?

2. Have you lost a file, or found it damaged upon opening it?

3. When starting your computer, has it failed to boot to the desktop,

invoking a blue or black screen, or an error message (write that message down)?

Accidentally deleted files can usually be recovered by File Undelete software, which lucky for you is the cheapest solution at about $30 USD. If you cannot locate a file afer running the program, the file system (where the files lie) may have been altered, deleted, or damaged. This means, File Undelete software cannot work, and you should use a “complete” file recovery product.

Lost or damaged files require a “complete” file recovery software, which usually costs about $100 USD. (Professional grade recovery software which include multiple recovery functions costs as much as $400). If you cannot locate a file after running the program, or if your computer failed to boot to the desktop, you may need File Recovery Services.

File Recovery Services…

A good rule of thumb at choosing a file recovery service company is, if they develop and sell file recovery software – not just sell them, they should have reliable in-lab services (After fifteen years of developing file recovery software, and knowing who is who in the industry, I can attest to this point). Also, full-scale recovery companies only do file recovery and computer forensics. So, ask a computer related question like, can you install a network with thirty computers? Yes means hang up the phone. Remember, you always get what you pay for and nobody works for free.

In conclusion, the saying in the industry is “file recovery is not, if it will happen, but when will it (and will you be prepared).” Prevention is the best solution. So, to ensure the safety of your files in the future (not to mention the hassle of having to go this process again) consistently do the following:

1. Back-up files daily to a secondary storage device, not on the main hard disk drive where you originally saved them.

2. Defrag your computer regularly. Doing so will increase the probability of a successful recovery if you ever encounter this problem again.

3. At least once a month confirm your back-up is working properly. This is a common problem.

About The Author
Ken Roberts
You can find more written, audio and video information discussing the data recovery industry at ACR Data Recovery. Ken Roberts has been developing data recovery software and performing data recovery services worldwide for over 15 years.
http://www.atl-datarecovery.com/

What are Windows registry? Why are they so important for your operating system? What can you do to keep them reliable?

According to Microsoft site, registry are “a central hierarchical database used in Microsoft Windows … to store information necessary to configure the system for one or more users, applications and hardware devices.” You can add to that data regarding file types like what application is used to open them, what icons should be display for them and so on.

I will try to explain what’s happening on 2 of the most common scenarios that take place on your computer:

1. You get a new program (software or game). You want to give it a try, so you install it. At that point, new data is written in your windows registry. That data include program folder, associated files, various settings that are used by the program, whether it will run on startup (HKCU/Software/Microsoft/Windows/Current Version/Run/ ) or only at the first startup (HKCU/Software/Microsoft/Windows/Current Version/RunOnce/ ).

No problem so far. But what’s happening if you decide to uninstall it? That’s that point where things get tricky.
Even if you receive a “successfully uninstall” message, pieces of data remain in your registry. Of course, this is not happening on all cases, but sadly it does in many of them.

In a worst case scenario, if for instance files “*.abc” are registered to an application that you just removed and the whole registration process wasn’t properly removed from registry, you will get an error when you try to run that sort of files. Those invalid registry entries won’t bother you visibly all the time, but they will cause your computer to slow down or even crash in some cases.

2. You install some new hardware, like another network card or something. When you plug it in, Windows will detect it and install the best drivers for it. Of course, a significant quantity of data is written into registry. Again no problem so far. When you shutdown you computer and remove the just installed device, registry entries are not deleted. They just remain there. If you try, after a period of time, to install a similar device, conflicts may appear, because you computer might confuse them. This is happening because of the old and possibly corrupt registry entries.

A solution to avoid those kind of problems is to create regular backups of your entire Windows registry. That way you can easily restore them the moment you feel something is not working right. But be careful, because an old backup might cause your newest programs or hardware devices to malfunction. Another way to solve the problems is to use a registry tool that would parse your registry and fix all invalid, missing or corrupt entries that it could find.

You can visit CoreDownload, a software archive with more than 23.000 programs where you will find a variety of registry tools that can fix all your problems.

About the author:
Ted Peterson writes for CoreDownload – Download essential games and utilities. Purchase online having up to 20% discount of the initial price for popular titles like Registry Mechanic.