How to Format a Computer

Do you need to format your computer? Let me explain

A person formatting a computer-min

The first thing we must take into account is that at the moment of formatting a PC we will be deleting all the information in the unit and a new file system will be created, so you will lose all your saved information.

If what you need is to format PC to install Windows from scratch, or to start using it with the installation of the extra unit, then you can do it to erase all the information you have in it and “start over”. But in addition, you can also use a Windows bootable CD to reduce the size you have in drives and format the rest that is free or create a second partition in your PC. In other words, you would split your hard drive storage in two.

If you are going to replace or sell your computer, then the best thing to do is to format the PC and remove all the sensitive data that the computer may contain. This way, its next owner will not have access to it and you will avoid possible “scares” since we all have private information and/or images in our personal computers. Whatever the reason you want to learn how to perform this process, here we will explain it to you step by step through detailed guides specific to each system. Learning to format has never been as easy as with us!

If you have a MAC computer, the process is slightly different than with Microsoft’s OS, so we suggest you follow the link to copy our step-by-step tutorial guidelines on how to format a MAC. Moving on!

Formatting the primary drive of a PC

Before starting the formatting you have to back up all the information you consider important. So make sure you back up all your files, either by using an external disk or by renting services in the cloud.

In case you just want to throw away your PC and delete all the data safely, you must insert the Windows installation disk to format the drive. This is the easiest way to do this, as you cannot do it from the desktop environment itself. For this, you don’t need to use your installation disc, because you wouldn’t have to reinstall Windows if this is the case and you don’t have the installation CD there are a couple of alternative solutions to format windows without CD and achieve it. We mention them one by one classified by each version of this operating system.

How to format the different versions of Windows if you do not have the disc

Windows 7

You can download the ISO file for this version of Windows from its official website, although you will need a product key to be able to activate it. If you don’t remember it either or you don’t have your original one (which came with the Windows 7 installation CD) you will have to buy it. Even if you have all the data downloaded in a bootable drive or another CD, the only way to make it a functional operating system is by using the official product key. Luckily for you, you can buy a windows 7 key online and you will receive your access key instantly. Save it well, as it will be useful for all the computers where you want to install this version of Windows in the future. Once you get the original Windows 7 serial, transfer the ISO data to a USB drive or CD that is completely blank using the burning tools that you find easiest. You’ll be ready to format windows 7 and use it as you see fit.

Windows 8

Again, you will need to download the media file creation for this version. The program burns either on a DVD/CD or on a USB that must have a capacity higher than 4 GB since that is what the ISO file of Windows 8 occupies. You must also have the official Windows 8 key or you will not be able to use it, and you will not be able to format windows 8 correctly. That is why, and if you don’t have it thanks to computer purchases in the past, our recommendation is to buy a windows 8 key online and, instantly, you will receive it. You will be able to use it infinitely in the future. There are many offers on the network through which you can buy cheap windows keys, so be aware of them and take advantage of the best market prices. Once you meet both requirements, proceed to burn the ISO image of windows 8 in a CD or a USB in order to have your boot disk and run it as you wish, either to create a new partition or format windows 8, renewing the system to its factory settings.

Formatting Windows 10

Again, you will need a genuine key to access the OS. You can buy a Windows 10 key from Microsoft’s own official website, or look for online offers that significantly lower the cost of it, the decision is yours. Once you have the windows 10 serial for free or paying, you must proceed to download and save the ISO image with the operating system data. As we have explained before, you can do this on a DVD/CD or a USB, it all depends on your preferences and the burning tools you are going to use for this process. We recommend both equally, as they are quite simple and practical. Keep in mind that you can always re-burn another boot disk as long as you don’t lose the windows 10 serial, being this the most important thing since otherwise you won’t be able to format windows 10 and you will have to buy a new one.

After downloading the Windows 10 ISO image, the program to create an installation disc for this version of Windows runs. Take a good look at which version you are going to use first before creating the boot disk. Almost all Windows 10 users download the 64-bit version. If your PC’s ram has more than 4 GB, this is the option for you.

The following steps to format a PC

Once the problem of formatting Windows without a CD has been solved, the next step is to set your computer to boot from the installation drive, in this case, the DVD or USB drive, instead of the hard disk. This process depends on your computer and you will have to enter the BIOS to carry it out. We explain step by step how to change the boot drive from the BIOS below:

If it is Windows 7 (or older versions) you must restart your computer and press the BIOS key (f11 by default), then you go to the settings when it starts. If pressing the F11 key doesn’t work, try the following: F2, F11, F12, and DEL. These are the ones that activate this step by default, independently of whether you use a desktop PC or want to format a laptop.

If you are using Windows 8 (or other newer versions) you do it by pressing the power button, press the Shift key and hit Restart so you can open the Advanced Start menu. Then press the “Troubleshooting” option and then “Advanced Options”. Go to UEFI Firmware Setup and open the Start menu. You can configure the unit you chose for installation as well as the initial boot device.

Now you have to start the configuration process. For this Windows will load all files and then start the process. You will only be asked to select your preferred language and to accept the terms and conditions, starting later with the OS installation.

Which type of installation to choose

If you select Custom Installation, you will be able to reset the disk during installation. Now select the partition you want to format. After completing the primary installation, all disks and their partitions will appear. Most likely, you will have several partitions.

It is possible to delete the partitions on a single drive and combine them into another “Unallocated” partition. With this option, you can delete all the information on this one. You must click on the “Drive options” button and then the Delete option will appear. Be careful to delete all the partitions, because in the future you will have to create at least one new partition before you can format it. What you need to do in this case is to select the space that has not been allocated and click on “New” so that you can create a new partition and perform the process on it. You can then set new sizes and create up to four partitions on the same drive.

How to format the selected partition on your computer.

You must click the “Format” button, then select the partition or drive. If you can’t see the option, then click on the “Drive options” button, this will bring up the formatting option.

The same system will warn you that the selected process will delete all the information contained in that partition. When you accept the process, the drive will start formatting automatically and there will be no going back, so if you have come this far and haven’t backed up your files yet, this is your last chance!

Install the operating system

Formatting your PC’s main drive will delete the operating system, so you will not be able to use it until you reinstall it. You can install Windows after formatting the drive or any other system, such as Linux.

In the case of installing Windows, you can follow the instructions provided by the Configuration program after you have completed the formatting.

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To install the Linux operating system or any other OS, you need the installation disk of that system. In this case, we are focusing on Windows as it is the most widespread, but on our website, you will find tutorials on how to format Linux and other operating systems.

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Resetting the secondary drive of a PC

For this option, you must open the “Disk Management” utility. When you install a new internal disk you must format it before it appears in Windows. To do this you have to do the following:

  • Press the Windows icon and R and type diskmgmt.msc so you can see the Disk Management utility. If you have Windows versions 8 and 10, right click on Start and select Disk Management.
  • All the disks you have installed should appear
  • Now erase the information from the unit safely.

You can also create partitions on the drive. You have to select GPT if it is a 2 TB disk or has more capacity. Or select MBR if the disk is less than 2 TB.

Now select the drive you want to format. If you only installed a new drive, it should appear in its own row with a label that says Unallocated. What you should do is expand the Status column so you can see the details of each partition.

You should know that you cannot format the boot partition since that is where the Windows operating system is installed. Formatting the drive will delete all the information, so it is important to make sure you select the correct one.

You can create a partition if necessary. In case it says the drive is not assigned, right-click and select “New Single Volume”, then follow the on-screen instructions to create a partition of that unassigned space.

Formatting PCs securely

Proceed to download DBAN

This is a free tool that serves to format hard disks and can overwrite all the information so that it cannot be recovered. If you are going to throw away your PC, give it away or sell it, this is an option that assures you that your identity will not be stolen or any other type of data that you have saved at some point in your computer since you will delete all your data from the hard drive completely.

You can download this tool from Please note that you cannot use it to delete SSDs, for this you need to pay a service.

You can copy DBAN to a blank DVD or CD. It is a light format so it fits perfectly on a CD or DVD. If you’re using Windows 7 or a more recent version, right click on the ISO file you already downloaded and select “Copy Disc”. You have to make your computer boot from the disk, to do this you have to configure it to boot from the drive that allows you to open the DBAN tool.

Now start DBAN, after you have configured the startup, press Enter on the DEBAN screen. Then select the drive you want to clean. Use the arrow keys to select the hard drive and press the space key to select it. Now press F10 so you can start wiping and you can safely clean up all the information. This will make it almost impossible to recover any data.

If you want to be even more secure, then press the M key on the selected drive and choose the option “Dod 5220.22-M” or select “Gutmann Cleaning”. It will take a while to run but it is a “bulletproof” cleanup.