Does Formatting Really erase All Data?

Reformatting a disk does not erase the data on the disk, only the address tables. The good news is that if you accidentally reformat a hard disk, a computer specialist should be able to recover most or all the data that was on the disk. The bad news is that for any business or corporation that is planning to donate old computers to charity, this could pose a security risk if that computer disk drive contained confidential business information. Remember — just because you may donate the computer to charity that doesn't mean an honest person will end up with it. While that shouldn't deter you from recycling old computers in this way, it should be an incentive to ensure all business data has been completely wiped from the hard drive. Never just delete the files and assume they are gone because you can't see them on the hard drive. Businesses should at the very least run the format command to erase the hard drive. The safest method to completely remove data is to overwrite the disk. You can do this yourself, although it is quite time consuming. To overwrite the disk would mean to format, then fill the disk completely with data, and format again. The easiest way to do this is to use a software program that will overwrite the disk for you. Most of these programs, which are often referred to as "Data Dump" software, will meet even the strict deletion requirements of the U.S. military. As an added bonus, a few good data dump programs can be freely downloaded from the Internet.

The Format Command

Format is a Microsoft DOS command. It's a command line you can run to remove information from a computer disk, floppy disk or hard disk. It is an external command found in many of the Windows Operating systems. Hard drive formatting is done in three steps:

(1) Low-level formatting creates the physical structure on the hard drive. Partitioning divides the hard drive into logical pieces that become volumes. High-level formatting defines the logical structures on the partition and places at the start of the disk any necessary operating system files.

The format command syntax is the following:

FORMAT drive: [/parameters]

- where drive: specifies the volume to format (the hard disk letter followed by a colon) — example format c:

— where [parameters] formats the disk with different options — example format c: /s will copy system files to the formatted disk or format c: /q performs a quick format.

The syntax used between Windows 95, 98 and ME differ slightly from Windows 2000 and XP. To see the available Format command parameters for your operating system, you can type FORMAT /? at the DOS command line.