It is true that when you delete data on the hard drive, the physical proof of its removal is removed; but, the data itself continues to be stored in its original location until it is overwritten.
It is possible to replace data that has been removed from the hard drive of a computer if you so want. This will take some time, but in the meanwhile, it is possible to restore the data.
Overwrite the data on your hard disk with a software that alternates between writing 1s and 0s until it can no longer be retrieved. This should be done many times.
To make sure a file is truly gone, a number of tools are available. Eraser is a free and easy-to-use solution that will overwrite your private information with random patterns until the data is no longer recoverable. It works with nearly every version of Windows and offers a number of methods of overwriting your data, including methods approved by the Department of Defense.Source: PCWorld
If you need assistance with hard drive issues, please give us a call at 1-800-620-5285. Karls Technology is a nationwide computer service company with offices in many major cities. This blog post is brought to you by our staff at the Summerlin Computer Repair Service. If you need computer repair in Summerlin, NV please call the local office at (702) 800-7850.