A hard disk drive (HDD, or also hard drive) is a fixed data storage device that stores data on a magnetic surface layered onto hard disk platters.

A hard disk uses rigid rotating platters (disks). Each platter has a planar magnetic surface on which digital data may be stored. Information is written to the disk by transmitting an electromagnetic flux through an antenna or read-write head that is very close to a magnetic material, which in turn changes its polarization due to the flux.

The information can be read by a read-write head which senses electrical change as the magnetic fields pass by in close proximity as the platter rotates.

Disk failure occurs when a hard disk drive no longer operates and the information on it can no longer be accessed by the computer.

This can happen for no reason at all or due to an external factor such as exposure to fire or water or High Magneticwaves or suffering a sharp impact
How seriously the disk failure is varies.

The most serious and well-known kind is the head crash where the internal read-and-write head of the device touches a platter or a magnetic data storage surface. A head crash normally causes severe data loss and, moreover, data recovery attempts may cause further damage if not done by somebody with specialized knowledge.

There are also controller electronics which occasionally fail. If that happens it may be possible to recover all data.

When your computer’s hard disk starts to act funny, make sure that you have an up-to-date backup. Then you can prepare some simple diagnostics and possibly repairs. Both Windows and Mac OS come with built-in hard-disk utility software that scans your hard disk for errors and attempts to fix them.

This is what you can do for Windows Steps: 1. Double-click on My Computer to open the My Computer window. 2. Select the disk that you want to diagnose and repair. 3. Choose Properties from the File menu. You can see the Properties window for the drive that you selected. 4. Choose the Tools button. 5. Click the Check Now button under Error Checking Status. 6. Choose either "Thorough" or "Scan for and Attempt Recovery of Bad Sectors." 7. Click on Start.

Tools to recover data are various such as:

There is a Data Recovery Utility which examines your inaccessible hard drive for damages and corruptions and recovers the data back.

Hard drive can be recovered from Windows 9x / ME / NT / 2000 XP / 2003 disk recovery
Supports FAT16, FAT32, NTFS, NTFS5 file system
Provides data recovery from Formatted logical drives
Recovers data from Re-partitioned & Missing/ Lost Logical drives
Lost folder and deleted file recovery.

There is also a partition recovery utility available that helps you in recovering all your important data lost after accidental formatting, virus problems, software malfunction,and file or directory deletion. There are also easy to use FAT & NTFS Partition File recovery Utilities that examine your inaccessible hard drives for damages and corruptions and recover the data.

There are also systems which:

Provide Partition recovery from FAT16, FAT32, NTFS, NTFS5 file systems. Recover deleted files/folders even after recycle bin has been emptied or use of Shift+Del key. File recovery from deleted partition, lost partition missing partition or formatted logical drives.

File recovery from Missing or Lost folders.

Recognize and preserve long file names when restoring files & folders. Multi-Disk Drive Support - Performs NTFS recovery on all IDE, EIDE and SCSI disk devices.

There is also software that recovers corrupt or lost data from floppy disks.

Many sites dedicate themselves to all manner of disk repair in fact we have found some fantastic information, The types of disk repair information available are information about hard disk and hard drives, DVD discs and CD disc.

By disc repair a site can either cover the complete repair a quick repair or both. Well we are all for quick repair and possibly the most asked question about repairing disk refers to DVD’s now days these are taking over as the number one entertainment method and as it becomes more popular we are finding that people are having tons of trouble with DVD disks.

This article will be dealing with a quick repair of DVD’s because this is the most frequently searched subject and in coming years going to be invaluable as all our old video tape information gets transferred to the new media. We will quickly cover some of the more severe methods.

Resurfacing DVDs , this relates to a special machine that will actually resurface and remove any large scratches in the dvd and actually gets to the bottom of an scratches that aren’t that severe they require more complex repairs suck as this an this machine actually removes layers of the DVD coating. Another DVD resurfacing method used for disk repairs are polishing the DVDs this can be done at a local DVD rental shop and works most of the time while not being quite as severe as the machining method it is good for 85% of all DVD scratches but again this has limited us , no more than 5 times.

Available now are nifty little machines that you can purchase for many major discounters like big w in Australia and Wal-Mart in the us these machines are smaller versions of the DVD shop ones and offer a repair at a discount , that you can use multiple times.

WHAT WE HAVE FOUND

The good news is we have found by far most DVD problems relates to damage that is not severe enough to warrant using the above methods. The good news is that 90% of all damage is caused by finger prints and dust, that right something as small as s smudgy print can stop your copy of die hard 4 from working. So without all of the above complex repairs you can purchase a cloth and material along with DVD cleaner to wipe of these prints and bingo your DVD is in number one condition. The best way we have found is to wipe in a circular motion not with the groves of the DVD , especially follow the information on the kit.

But something important remember disk repair is the same with everything prevention is better than cure. By this we mean when moving and removing the disk you must be extra careful and never touch the front of the disk (shinnyt side), we know this sounds difficult but in act it is easy use the whole in the centre and also the edges of the DVD to move it around and your DVD will last for years.

Caution: the most damages happen when removing from the case so this is a time where extra precautions should be taken.

Computers have become more widespread than ever, with every business and organization usually relying to some extent on these information machines. They facilitate the performance of many otherwise tedious tasks within any organization, and really help to boost productivity.

For instance, there are programs called word processors for creating any sort of printed communication, from letters to memorandums. There are also programs called spreadsheets that can perform calculations and display data and results in tables and graphs.

There is also software available for making databases, which are organized collections of data such as transaction information, employee information, and so on. These databases make it easy to store important information in an easily accessible form.

Sometimes, confidential information might need to be stored digitally, in some form or other. When this is the case, there are usually built-in security measures to help keep the precious data protected. However, it might arise that a hard disk would be reallocated, or that the computer itself would be transferred to some other use.

In this case, it becomes necessary to completely wipe the disk; that is, delete all the information on the disk, along with any traces that might be used to reconstruct this information. This is good computing practice, even for non-critical hard disks. Wiping down a hard disk does not take much effort, nowadays, since there are programs and the like available to do it for you. Getting used to wiping down hard disks to be deleted completely costs virtually nothing in the way of money or effort but pays off in the formation of a useful habit.

There are disk wipe programs available designed for big businesses that might need to do it in large batches. These programs have features that make it easier to keep track of the many hard disk volumes to be wiped. Some can even automatically retrieve and store serial numbers, for instance to comply with legal requirements.

Users of personal computers may also sometimes find it necessary to completely erase the data on their hard disks. When selling an old computer, for instance, it would be a good precaution to do a complete wipe-out of the data to prevent any possible identity theft.

Simply deleting all files (using the current operating system, for example) may not be secure enough. There are known ways to recover data from a hard disk that has not been wiped cleanly enough. The traces of data that remain in some “deleted’ hard disks are sometimes enough to be analyzed and used to reconstruct pieces of information presumed lost.

Apart from security purposes, using these disk wipers can also help when reinstalling an operating system. For systems that are heavily infected with viruses and other malicious software, a complete disk wipe and clean reinstall may be the more convenient solution.

There are both free and commercial applications available for wiping disks. Commercial ones are of course not free, but usually technical support for these are readily available. It becomes a matter of choice whether to select a cost-free but unsupported disk wipe program over a commercial program, or vice versa

Data security has become a bigger concern as the information age goes into full swing. Computers are becoming more and more commonplace as versatile tools for a wide variety of tasks and uses. This has made digital storage increasingly the data storage format of choice, since digital information is easily accessed and processed by computers.

This has led to a rise in interest in digital information and data storage systems. Apart from developments in hardware technology that allow bigger capacity devices with faster access times, security has also become a prime consideration. Most software and programs nowadays come equipped with varying levels of security options. For instance, it is now possible to protect almost any file with a password such that only those who can provide the correct password would be able to access the information within the file.

However, these software security measures would not stand up to dedicated data extraction efforts, in particular those involving the actual physical hardware. Physically securing the hard drive (or other data storage device) under consideration may not always be possible or practical. Another way of ensuring that important data is not placed at risk is to wipe the disk.

Simply deleting the contents of a hard disk is not enough to ensure that they are not recovered. In fact, there are software utilities that allow the recovery of deleted data. This possibility is because when a file is deleted, it is not actually overwritten or removed from the hard disk. Instead, a marker is just associated with the file to say that it has been deleted, and the space it occupies on the disk is marked available for use. This means that the data in the file remains on the disk for the knowledgeable hacker to extract and view.

Wiping a disk, on the other hand, is a much more thorough process. In a disk wipe, all data to be wiped off is actually overwritten with random data. This eliminates almost entirely the traces that a normal deletion leaves behind, and makes recovery of data practically impossible. (In theory, it would still be possible to reconstruct the data lost after a hard disk wipe, but this would require high-powered microscopes and would proceed much too slowly to be useful!)

Performing a disk wipe is facilitated by the many disk wipe programs available. There are many free options, as well as commercial software options, which may differ in terms of functionality and documentation. The majority of these are available online, which makes it quite easy to browse through and find the most appropriate program for the specific task. Some programs are designed for use on a single personal computer, while others may be designed for use on batches of computers.

Confidential data that needs to be kept from being exposed may best be hidden by using a disk wipe. This simple additional security measure makes the recovery of deleted data nearly impossible. With the many disk wipe programs available, it is easier than ever to perform a disk wipe, even for casual users, making this a real data security option.

Computers and their accompanying technologies have definitely revolutionized many aspects of human endeavor. With their amazing capabilities for handling and processing large amounts of information in far less time than humans could have, computers have made many tasks faster and easier. Their big advantages have led to them being ubiquitous in the modern world. Computers are now in use almost everywhere, handling many different types of data. They also now deal with private data as well as confidential data that need to be kept secure.

Many security measures exist to protect digital information. The most old-fashioned of course is to physically keep the computers under lock and key. But this approach is neither foolproof nor always possible to take. There also exist various software security measures that range from simple password protection to sophisticated encryption systems. But again, these measures are not foolproof, and some of the better systems might be too work-intensive to use for low- to medium-security applications.

For information that needs to be securely removed from a hard disk, wiping the hard disk is almost obligatory. This is because it is rather easy to perform, while at the same time being very effective. To understand how a hard-disk-wipe works, it would be best to first look at ordinary file deletion or hard disk reformatting.

In these processes, what is modified is simply the metadata, or the information stored about the data. That is, when a file is deleted, a tag or marker is set to ‘deleted’, and the file is removed from its directory listings. Because it has been marked as ‘deleted’, it will be overwritten when new data is put onto the disk. However, it is still not a certainty that deleted files will be overwritten. And besides, this means that there is time between deletion and overwriting during which the data is still on the hard disk and able to be recovered. Reformatting a hard disk consists mostly of the same processes, but applied to all files on the hard disk.

A disk wipe, on the other hand, physically overwrites the data on the hard drive with random sets of data. That is, the data is garbled by the disk wipe software to make it almost impossible to be recovered. The entire hard disk is then overwritten with random data so as to eliminate all traces of the data that was previously on the hard disk. The benefit of performing a disk wipe is obvious. The chances of recovering deleted data from the hard disk are greatly reduced and almost disappear.

And it is rather easy to wipe a hard disk. All that is needed is a copy of the disk wipe software to be used on some removable storage media. Typically, when this removable media is connected to a hard disk, the disk wipe software automatically executes and performs the wipe. This makes it possible to perform disk wipes in bulk, which is a good thing for companies and large organizations.

In summary, it is easy and effective to wipe a hard disk. This additional security measure can really help ensure that data remains inaccessible, while not being too work-intensive.