There could be any one of many reasons why you would want to wipe your hard drive, but they all relate solely to the need to completely remove information. If you are selling a computer, or even throwing a computer away, it is possible for somebody to find sensitive information on your hard drives. Remember that word document that you used to list all of your Internet passwords? That spreadsheet that you made that gives a little too much information on your business systems? Those files will still be somewhere on your hard drive, and they will be until you either a) throw your hard drive into a furnace, or b) follow my instructions.

An index of files is maintained on every hard drive, this index tells the drive where information is stored. When you install/save a file, it is often scattered across the drive in different locations. When you command your computer to open a file the hard drive consults the index, before gathering the pieces and reconstructing them into a whole. When you choose to delete/uninstall a file the links between the files and the index disappear, meaning that your drive no longer knows where to find it. This tells your computer that the file is no longer required and that the relevant space on your hard drive can be overwritten. This deleted file actually remains in the drive until it is overwritten, which unless you completely fill your drive will probably never happen. Even a file that has been overwritten can be recovered by somebody that really knows their stuff. If for example you were planning on selling your computer, and just deleted everything, it is likely that much of this information still exists for anybody with a shareware program to find. I cannot emphasise enough just how important it is to wipe your drives no matter what you are going to do with it, even those that are giving a computer to their dear old auntie Sophie; you don't know whether Sophie will throw that computer away in a years time, ready for pickings by the local fraudsters.

Reformatting a hard drive prepares it for a complete installation or reinstallation of an operating system, and that is your goal. All versions of Windows prior to Windows XP allow you to create a start-up disk, you need this to reformat your drive. You can do this by:-

Start > Settings > Control Panel. Click 'Add/Remove Programs', then 'Start-up Disk', then 'Create Disk'. Then follow instructions to burn your start up disk.

On Windows XP you have to download this start-up disk info, you can do this by visiting www.bootdisk.com and clicking on 'DOS - Windows 9X/NT4/2000/XP Excellent Bootdisks', download the Windows XP Custom Install Disk and save it to either CD or Floppy. Then restart your system with the floppy/disk in the drive and follow on screen instructions (this is easy).

For Windows Vista, you should have an operating system disk. If you do, you just need to insert this, reboot your computer, and follow the instructions. This should reformat your drive in the process (they have made these things a lot easier). If for some reason you haven't got an operating disk, then sorry, you will have to either a) buy another one, or b) do whatever it was you did to get your operating system in the first place ;)

If you don't know much about computers, or just want to make sure that you get it write, there are some fantastically effective software's out there. They guarantee that your files cannot be found after the software has finished filling your disk space with complete nonsense. And this could be the safest route for anybody that is giving their computer away, once such program is Norton SystemWorks which includes an excellent application called 'Wipe Info' which is considered in industry as fail safe. Another is DataEraser by OnTrack, which has an equally excellent reputation. Although there are thousands of applications that claim to offer the same quality service, please be careful to buy the software of a solid and established brand. These software's do take a while though, normally long enough to justify leaving it running overnight!

If your information is really that sensitive, or you are just that damn paranoid, or you are throwing your computer away anyway....... then there really is just one option. And that is DESTRUCTION!!! To do this you need to:-

1. Unplug the wires on the hard drive and remove the screws, slide the hard drive out.

2. Then read my forthcoming hub '5 Great Ways To Destroy Hard Drive Data'