Formatting and erasing are the two possible ways to wipe data from hard disk. The general misconception made by most of the users is formatting erases the data from disk entirely. Actually, formatting does not erase the data permanently. When you format drive, only the linking index is erased and can be recovered back easily using recovery programs i.e., data recovery is possible even after formatting also. You may spend more time to delete files one by one from your system or format using format command to erase the data. Deleting data or format are not the correct solutions to wipe data. Data wiping should wipe data permanently where recovery should become impossible using a suitable tool also. When you want to sell the hard disk or donate it to other users, you have to wipe data from drive completely. To dispose the hard disk that cannot be worthy to use in a system but it is still operating, wiping data permanently from disk permanently is suggested in this situation also. These are the most possible causes for complete erase of data from hard disk. Most of the users consider that reformatting also remove the data from disk. However, programs or data recovery tools can unformat the data and recover data from disk easily. Hence, it is always suggested to erase the data securely with 0 and 1 that overwrites every sector of the hard drive. Use the tool that should be worth enough to wipe drive securely. Erasing data with single pass might be recovered using best tools. So, multiple passes is always preferred to remove the sensitive data.
The government standard method (DoD 5220.22-M) use a medium level security to erase data and passes three iterations to completely overwrite a hard drive six times. Every iteration makes two write passes for entire drive. The first pass overwrite with 1 over the surface of the drive. The second pass overwrites with zero’s to the surface. 246 government designated code is written across the drive after the third iteration. The final pass use a read verify process and verifies that the data is securely erased.
Using commands like format or delete just modify the structure of the drive and data is remained on the drive itself. Some of the technical professionals can recover the data even after single pass also. So, depending upon the security level, erase the data by considering multiple passes. Select the best tool that erases the data automatically that is capable of wiping the data by beyond recovery.
I suggest using Remo Drive Wipe that uses nine sanitization standards to remove sensitive data from hard drive or logical drives by overwriting disk several times. This software is an advanced erasing tool that supports various operating systems like Windows 7, Windows Vista, Windows XP, Windows 2003 and 2008. This tool uses nine disk sanitization methods and assures that data is securely erased. You can download demo version of the tool where you can select the wiping algorithm depending upon the level of security you need.