Are Deleted Files Completely Erased?
A common misconception when deleting files is that they are completely removed from the hard drive. However, users should be aware that highly sensitive data can still be retrieved from a hard drive even after the files have been deleted because the data is not really gone. Files that are moved to the recycle bin (on PCs) or the trash can (on Macs) stay in those folders until the user empties the recycle bin or trash can. Once they have been deleted from those folders, they are still located in the hard drive and can be retrieved with the right software.
Any time that a file is deleted from a hard drive, it is not erased. What is erased is the bit of information that points to the location of the file on the hard drive. The operating system uses these pointers to build the directory tree structure (the file allocation table), which consists of the pointers for every other file on the hard drive. When the pointer is erased, the file essentially becomes invisible to the operating system. The file still exists; the operating system just doesn't know how to find it. It is, however, relatively easy to retrieve deleted files with the right software.
The only way to completely erase a file with no trace is to overwrite the data. The operating system will eventually overwrite files that have no pointers in the directory tree structure, so the longer an unpointed file remains in the hard drive the greater the probability that it has been overwritten. There are also many "file erasing" software products currently on the market that will permanently erase files by overwriting them.
Recommended Reading: How to Completely Erase a Hard Disk Drive
Key Terms To Understanding Deleted Files:
Related Articles on Webopedia:
Keeping track of big data trends, research and statistics gives IT professionals a solid foundation to plan big data projects. Here are 15... Read More »Enterprise Storage Vendors
There's a number of vendors that sell enterprise storage hardware or offer cloud-based enterprise storage. View Webopedia's Enterprise storage... Read More »50 Cloud Computing Terms Defined
From planning a private cloud project to finding an online cloud storage provider, Webopedia's A-Z Cloud Computing Glossary will help you... Read More »
- Enterprise Mobility Exchange results show continued growth and emphasis on mobility. CIOInsight breaks down the numbers here. »
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »
From the widest view, everything that we include under the heading of mobile has irrevocably changed IT's relationship with the rest of the... Read More »Choosing an Enterprise Storage Implementation
When you deploy a new enterprise storage system, you must decide whether to design and build your own storage system or to utilize a cloud-based... Read More »Big Data Analytics Expert Predictions
In this Webopedia Did You Know...? article we look at three big data expert predictions for 2014. Read More »