Computer viruses, general computer glitches, adding additional drives or selling your computer may require you to format the hard drive on your desktop or laptop computer. Formatting a hard drive causes the physical hardware to be tested and installs a file system on the drive. The file system, or hard drive software, allows the computer to access information on the drive through a folders and files directory structure.http://www.techterms.com/definition/format

New hard drives generally require formatting before they are recognized by your computer. Formatting makes them able to store information and software programs. Existing hard drives that have encountered a problem or will be reused should undergo an extra step to wipe out all existing information and data on the drive prior to adding the file system. Wiping out the drive first can help remove viruses or other problems.http://www.webopedia.com/DidYouKnow/hardware_software/2005/harddrive_format.asp

Formatting your hard drive is a process that you can perform yourself. You do not need any special tools because the formatting software is built into most standard operating systems. Back up any important information prior to starting the formatting process because the information on your drive will not be accessible after you have finalized the formatting process.http://www.techterms.com/definition/format

Back up all of the files on your hard drive to another location. You can place the information on another hard drive or external storage device. You can also use an automated backup program that copies information to an online storage site, network device or other location.http://www.udel.edu/topics/backups/

Make sure you have a copy of your documents, bookmarks, software data files, photos and multimedia files. If you are reformatting your hard drive due to a virus, be sure to carefully segregate your information and run all files through a virus check.http://www.liutilities.com/how-to/clean-a-computer-from-a-virus/

After you back up your files, make a list of all software programs you have on your drive that you will want to reinstall. Jot down any serial numbers or other data points that you will need to reinstall the program after formatting.http://www.webopedia.com/DidYouKnow/hardware_software/2005/harddrive_format.asp

Decide if you want to erase all the existing data on your hard drive. If you are planning to sell or dispose of your hard drive, you should opt to wipe out all information to prevent any identity theft problems.http://www.identitytheftfixes.com/can_getting_rid_of_a_computer_or_replacing_a_hard_drive_lead.html Additionally, if you are trying to recover from a computer virus, you should erase all data in order to start out with a clean hard drive. If you are planning to simply reinstall an operating system, you can bypass erasing your data if desired.http://support.microsoft.com/kb/313348

If you need to wipe out your data, you can purchase software or hire a company that can perform the task. The standard level of disk wiping used by the United States government is known as DoD 522.22-M. This medium-level security wiping requires processing the deletion to overwrite the drive at least six times to ensure the drive is clean and data-free.http://www.webopedia.com/DidYouKnow/computer_science/2007/completely_erase_harddrive.asp

If you plan to reinstall your Windows operating system as part of your formatting, follow the steps below.

1. Go into your BIOS and set the boot priority to start with your CD-ROM drive. Restart your computer and watch the screen for the instructions on which key to hit during the start-up process to enter the BIOS.http://www.hiren.info/pages/bios-boot-cdrom It is often the "Delete" or "F8" key. Hit the appropriate key when prompted, then look through the menus in your BIOS for a boot priority option. When you find the boot priority option, change it to boot from the CD first. Typically, you will select this option by using the arrow keys or "pageup" and "pagedown" keys.http://www.computerhope.com/issues/ch000192.htm
2. Restart your computer with the Windows disc in your CD or DVD drive.http://support.microsoft.com/kb/315341
3. Follow the steps to boot from the CD listed on your monitor.http://support.microsoft.com/kb/315341
4. Select to install a fresh copy of Windows.http://support.microsoft.com/kb/315341
5. Delete the current partition.http://www.whitecanyon.com/format-hard-drive.php
6. Select the un-partitioned space and create a new partition.http://www.worldstart.com/tips/tips.php/389
7. Choose your new partition and format it.http://support.microsoft.com/kb/315341
8. Continue with the Windows installation process as noted on your monitor.http://support.microsoft.com/kb/315341

If you do not want to install a Windows operating system onto your hard drive, follow the steps outlined below.

1. Make, create or download the files to make a boot disk.http://www.bootdisk.com/
2. Go into your BIOS and set the floppy disk or CD drive as the first boot device depending upon your boot disk medium.http://www.hiren.info/pages/bios-boot-cdrom
3. Restart your computer with the boot disk in the drive.
4. Choose to boot your computer using CD-ROM support.
5. Type the following command: "fdisk."http://support.microsoft.com/kb/255867
6. Select "Y" to enable large disk support.
7. Use this program to create a partition and set the partition to active.
8. When formatting is done, reboot with the boot disk again.
9. Type in the following command: "Format c:" in which c is the letter of your hard drive.
10. Type "y" to accept.http://support.microsoft.com/kb/255867

Check out these other helpful computer how tos:

1. How to Protect Your Computer From Viruses
2. How to Protect Your Computer From Malware
3. How to Back Up Your Computer Hard Drive
4. How to Build a Gaming Computer
5. How to Clean a Laptop Screen
6. How to Make Your Computer Run Faster
7. How to Start Windows in Safe Mode
8. How to Buy a Computer
9. How to Install Ram in a Laptop
10. How to Check for Windows Updates
11. How to Optimize Your Computer's Visual Performance
12. How to Optimize Your Computer's Virtual Memory
13. How to Check Your Computer's Wireless Security
14. Computer Keyboard Shortcuts
15. How to Optimize Settings in Control Panel