There are few moments as bad as the one when you realise that the report you were working on, your college work, family or holiday photos or other computer files seem to have vanished from your computer. But there is no need to get despondent. The chances are that your files are still there. Your computer simply doesn't know how to find them any more.

Causes of data loss

The most common reason for losing files is deletion. You deleted the files by mistake, or ran a disk cleanup utility that did it for you. The good news is that the data still exists. Only the pointers to where the data is have been deleted. If it has not been long since the files were deleted, the data will not have been re-used by another file, and there is a good chance of a successful recovery.

The next most common cause of data loss is overwriting. This is where you save a file using the same name as another one, destroying the original. This is not always as disastrous as it seems, because the computer may not have used the same bit of disk space to store the new file. The old data may still exist, even though it is no longer accessible by its filename.

File system corruption can result in missing files, corrupted files or even a computer that won't start up. Many people in this situation have thrown away their data, thinking that all is lost. In fact, this kind of problem is very often recoverable. Even if the system can't be restored to a state in which it will run Windows, Mac OS or whatever operating system you are using, it is generally possible to recover your data files before reformatting the disk and reinstalling the software.

Disk damage can result in read errors when you try to access certain files. This is often recoverable. Even complete hardware failure does not mean the data is lost. The magnetic encoding of the data on the surface of the disk is probably 100% intact, though you will probably need a data recovery service to repair the fault and make the disk readable again.

Recovering the data

If the data is still there, how to go about recovering it? Data recovery is a time-consuming process, and using a data recovery service is consequently expensive. There may be no other option in cases where the data is very important and the drive that held it is not accessible at all. But in most cases data can easily be recovered using do it yourself data recovery software.

Data recovery tools used to be rather technical in nature – and some of them still are – but you can now get data recovery utilities that can be used by the most non-technical of computer users. Such programs typically use a “wizard” – a familiar interface used by many different programs – to walk you through the recovery process. All you need to do, in essence, is tell the software where the data was held, wait while it scans the drive recovering files, and then examine the results, saving the files you want to keep to another drive.

If the data recovery software you choose doesn't find your data, it doesn't necessarily mean the data is not there. The best products use advanced technical algorithms to detect lost files where lesser tools miss them. As with most things in life, you get what you pay for.

With state of the art do it yourself data recovery software, losing important files from your computer is no longer the disaster it used to be. But of course, it’s still no substitute for backing up your computer data regularly!