There are many reasons to clear off your hard drive. Maybe you are upgrading to a newer operating system, or maybe your current system is cluttered and you want to start fresh. In any case, you will need to format your hard drive. What exactly does this mean?

Formatting a hard drive means to delete any data currently on the drive and create a new file system for the operating system to use. This is a simple process that is built into every operating system. For this guide, I will be formatting hard drives using Windows 7.

Note that data "deleted" when a drive is formatted is still potentially retrievable using special tools. I will touch on this more later in an optional step. This guide is primarily for users planning on reusing the formatted drive themselves. If you are planning on getting rid of your computer and are worried about your data being stolen, you will need to take additional steps to ensure that your information cannot be retrieved.

Step 1: Back Up Anything You Want to Keep

Chances are there are some files that you want to hold on to, so you can transfer them to your new system. You can either store these files on a flash drive or external hard drive, or use a cloud-based storage option such as Carbonite. So go through your file system and backup anything you want to keep. Be thorough, because once the drive is formatted, it will be difficult, if not impossible, to retrieve the data. Store any documents, pictures, videos, music, and so forth. Also don't forget things such as your bookmarks from your web browser, and if you are a gamer you will want to be sure to backup your game save data for games that don't use cloud storage.

Step 2: Formatting a Secondary Drive

Formatting a storage drive is a very simple process. Just follow these steps:

1. Open Disk Management. There are a few different ways to do this, such as through the control panel, or by typing "diskmgmt.msc" into the run utility, or most easily by just typing "disk management" into the Windows search box.

2. Find the drive you want to format in the list. Note that you can't format your main Windows drive from disk management; I will talk more about this in the next section. Right click on the desired drive and click "Format..." and then click "Yes" on the following confirmation window.

3. In the box by "Volume Label:" in the new window, type in the name you want to give your drive. You can leave it as the default "New Volume" or use a more descriptive name, like "Storage" or "Games." There aren't many reasons to change the "File system" or "Allocation unit size" options; in general, just leave them as "NTFS" and "Default." Also uncheck the "Perform a quick format" box. This will cause the format to take a while longer, but it will do a more thorough check for errors and will also do a basic overwrite of your old data. The "Enable file and folder compression" box can generally remain unchecked.

4. Click "OK" on the dialog box. This will open a new confirmation box. This is the point of no return, so be 100% certain that you are formatting the right drive, then click "OK."

5. Wait. It may take a while to finish formatting. You can keep track of the progress on the Disk Management screen. Once finished, the status of the drive will change from "Formatting:" to "Healthy." That's all there is to it; you can now use the drive as usual.

Step 3: Formatting the Main Drive (C:)

As I said in the previous section, you cannot format the hard drive that Windows is installed on through Disk Management. There are a number of ways to format your C: drive outside of Windows, however.

In my opinion, the best and easiest way to do this is to simply reinstall Windows. During installation, Windows automatically formats the drive and does a basic overwrite of your old data. A guide to do this can be found here.

However, if you want to format the drive without reinstalling Windows, a data removal tool called Darik's Boot and Nuke, also known as DBAN, is a favorable option. I will discuss this in a later section.

Step 4: Data Destruction (Optional)

The primary function of formatting a hard drive is hiding all the old data from the operating system and creating a new file system. Older operating systems, such as Windows XP, did nothing to destroy the old data, so it sat on the hard drive until it was eventually overwritten by programs on the new file system. Until this happened, that data was still there and easily able to be accessed with data recovery programs.

Newer operating systems put forth a little effort to hide your private data. As I said before, formatting hard drives or reinstalling the OS will now do a basic overwrite of old data by performing a one pass zero write. That is, all "empty" space on the drive is overwritten with zeroes. One pass of this is enough to counteract all data retrieval software, so it will stop your average Joe from accessing your information. However, there are other methods that skilled individuals can use to recover the data.

To truly destroy all of the data on your hard drive, so that it is not recoverable by any means, I suggest using Darik's Boot and Nuke, or DBAN. This program will allow you to do multiple passes of overwriting, with random data instead of just zeroes. To use DBAN, you will have to download the program, burn it to a CD, insert it and start your computer. The DBAN screen will then pop up and you can follow the instructions to wipe your drives.

Step 5: Maintaining Your New File System

For those that needed to format their hard drives because their systems became cluttered and slow, it is worth mentioning that it is not all that difficult to keep things clean and running smoothly. Regularly repeat these steps to cut down on unnecessary clutter:

1. Use the Windows Disk Cleanup tool. This tool allows you to get rid of temporary files that weren't deleted when the program that made them closed. These, and other junk files, should be removed regularly.

2. Use the Windows Disk Defragmenter tool. This tool makes multiple passes on your hard drive, consolidating fragmented files. This helps to make accessing files on the hard drive faster.

3. Uninstall programs that you don't regularly use. I am guilty of not doing this as often as I should, myself. This is especially important for people who play a lot of video games, because many games have their own launchers, anti-cheat programs, etc. These, along with the games themselves, build up over time and take up a large amount of space.

4. Cut back on programs that run on Windows startup. A lot of these programs can instead be started when needed to avoid a sluggish startup.