How to Format a Computer and Install Windows

how to format computer

What exactly is formatting? Formatting a PC involves wiping all the data on the PC and reinstalling the operating system in what is known as a “clean install”. This means that all of your current files are deleted, your hard drive partitions are reassembled into one big partition, and your operating system is wiped and reinstalled. This is the “nuclear option” for any computer user, and should be done only if you are experiencing the problems below.

Are you thinking about formatting your computer? Whether it is a laptop or desktop running Windows, Mac OS or even Linux, formatting usually becomes necessary at some point or the other, due to a variety of reasons. Here are some of the most common reasons why you would need to format computer data and reinstall your operating system.

Why You Would Need to Format a PC

windows format

If you have just bought yourself a new laptop or desktop computer, you may need to format it if you want to install a different OS to the one that it comes preinstalled with. For example, many Dell laptops tend to come with Ubuntu preinstalled onto the machine. If you are a Windows user, you can simply format the laptop to a standard installation of the OS. Other errors may also lead you to having to format your laptop or PC.

  1. Computer doesn’t start up – this is a common issue, once known as the black screen of death. While you can spend a wad of cash trying to repair your registry and fix the issue, it is typically cheaper and easier to simply reformat and reinstall Windows, Mac OS or Ubuntu.
  2. Cluttered hard drives – after a while of using your PC, you might find that a lot of your downloads don’t complete because you have no disk space. Cleaning up terabytes of hard disk space can take days, in which case it might be a lot more efficient to just learn how to format a computer.
  3. Error Overload – If you have more viruses on your computer than the CDC does in its secure labs, you probably are experiencing so many errors that working is impossible. In many cases, these viruses are so deeply integrated into the system that deciding to format a computer system is the only way to go.

There are many other issues too, including a slow, laggy computer or to upgrade a system, in which case you will need to learn how to reformat a computer with Windows 10 or whatever other OS you want to use. The bottom line is that you format your computer when it becomes impossible to use with ease any more, and you have no immediate solutions to the problem.



Formatting your PC erases ALL data on your hard drives permanently. Back up any data that you need to (if you can) before formatting a computer on Windows 10, 8, 7, Mac OS X or Ubuntu 11.1!!!!

A good common practice is to regularly back up all your important data onto a different hard drive or location. If you don’t do this, make sure you back your data up elsewhere BEFORE you decide, “Hey, time to format my computer!” and destroy everything!

You can back your stuff up in many ways including simply plugging an external hard drive or USB stick in and copying your important files into it using the copy/paste function. Another great way that is a little less secure is to use a cloud based storage like Google Drive, iCloud or Dropbox. While the storage space offered for free might not be enough for your 2TB of game data, you can buy a monthly storage space subscription for a ton of extra space. The final way is to perform a full backup of your PC using Apple’s Time Machine or Windows Backup.

Both of these have a unique way of creating backups that involve them only being compatible with the same type of operating system. This means that if you use the Windows Recovery Disc utility on your Windows system, you are only going to be able to restore the data to another system running a Windows OS. We generally do not recommend that you make use of these unless you plan on reinstalling the same OS again, because the files simply won’t be accessible from another computer system. Using the file explorer on any system to manually copy and paste files into your external storage is one way in which you can ensure that all of your files are easily accessible from anywhere, at any time, even while you are formatting your normal computer.

Think You’re Ready to Learn How to Format a Computer? Think Again!

how to format a computer

Before you scroll all the way down trying to format your PC quickly, make sure you backed all your data up. Check, recheck, and check again. We’ve got a handy checklist of important areas of your computer or laptop that you may not have backed up right here:

  • Files and folders – check your Documents folders, all subfolders as well as the root folder of your device’s hard drive(s). Many people fail to realize that at some point they went ahead and hid some of their most sensitive documents in different locations. Go back through your entire file system to make sure that you haven’t missed a single file or folder. This includes all your music, videos, game data, save files, documents, settings and notes.
  • Applications and Drivers – While you might not want to back up an entire game, the installation files (such as .exe for Windows computers and .tz for Mac) might come in handy, especially if they are hard to find again. Back up the setup files for your important hardware drivers as well, if you don’t have the DVDs for them. Thankfully, most current gen OS installation media has basic drivers built into it. You typically won’t have to manually install drivers for your hardware unless they are peripheral devices that aren’t classified as Plug and Play.
  • Browsers and browsing data – While you might not want to store ALL your browsing data, you should export your bookmarks and other information. If you have been using Safari or Google Chrome, signed into your Apple or Google account, these are linked to your account and won’t be a problem.

Run through the checklist at least three times so that we won’t have to sign on to find angry emails from you guys complaining about lost data. BACK. IT. UP.

How to Format Windows PC

format a windows pc

Deep breath. Okay. Time to learn how to format a computer. There are many different operating systems in the digital world today, and while the principle of formatting them is the same, learning to format and install Windows 10 is different (in little ways) to Macintosh or Ubuntu. You can learn here how to format a hard drive and reinstall Mac OS X, Windows 10, Windows 7 and Linux’s Ubuntu OS. While Windows tends to be a little more complicated, you shouldn’t have a rough go of it if you are following all the instructions.

Windows 10

WARNING: Back your data up!

  1. Make sure you have an installation disc for Windows 10. You can buy the disc or download it online and write it to a DVD or USB drive using the Microsoft Media Creation Tool (freely available here)
  2. Launch the tool and choose “Create Installation Media for Another PC”.
  3. Choose a language and version that you want. You chose the version when you bought Windows 10.
  4. Choose the media type (flash drive, CD/DVD, etc.). The easiest would be a flash drive.
  5. Hit Next and wait for the process to finish on its own. Keeping your flash drive or DVD in your computer, restart your PC.
  6. At the first boot screen (usually the logo of your desktop or laptop manufacturer) press F12, F11 or a similar function key to launch the boot manager and system BIOS.

Note: while you can install Windows 10 like a normal application, we’re writing this guide for people who can’t even turn their computers onto their desktops.

  1. A list will appear of startup devices. Pick the flash drive from it and press Enter.
  2. The Windows 10 installer will appear, and will ask you to fill out basic information. After this, you will be asked how you would like to reformat and reinstall Windows 10. Choose “Install Windows Only” or whatever option warns you that you will lose all your data.
  3. Choose the Primary hard drive partition for the install.
  4. Select “Delete” and then “New”, before pressing the all-powerful “Format” button.
  5. You will be guided through the rest. It will take a while, and your PC will restart a few times on its own. DO NOT TOUCH IT.
  6. All done! You will be taken to a very fun loading screen before being allowed to use your brand-new PC.

The process is pretty much the same for Windows 8.1 or Windows 8. We highly recommend freely upgrading to Windows 10 while you can if you are on these systems.

Note 2: If you aren’t having any issues with your PC or laptop, you won’t need to perform a clean install by booting from a disc. You can just launch the W10 installer from the media you created, like you would a normal application. All the same options are available, even if you are looking to do a full format of the system.

Windows 7

Warning: Back your PC up. We won’t tell you again. Okay, we will.

  1. Ensure you have your Windows 7 installation CD. If you don’t have a DVD, download the image from Microsoft and burn it to either a flash drive or disc using the Media Creation Tool. See steps 1 – 5 above for instructions on how to do this.
  2. Restart your computer, and press a Function key (F2, F10, F11 or F12) to enter your BIOS.
  3. Select the Boot option from the menu that appears.
  4. Change the boot order to either Boot from CD/DVD-RW OR to Boot from Removable Storage, depending on the type of media you will be using.
  5. Save and exit, and wait for your PC to restart. Make sure your flash drive or DVD is in your computer or laptop.
  6. You should see a message that prompts you to Press Any Key to boot from CD.
  7. Press any key.
  8. Windows 7 will begin to unpack files and get the setup wizard ready. Watch it happen.
  9. Pick your region, language, time and date, currency, keyboard and all the rest.
  10. Click on Install Now.

Do not click on Repair Windows, even if you are trying to fix errors. We will be doing a full format of ALL your files, not just trying to fix your OS.

  1. Accept the EULA (terms and conditions), and then select Custom Install.
  2. You will be given the option to pick the hard drive partition for your Windows 7 install. Delete all your old partitions by selecting Advanced Drive Options.
  3. Select all your partitions and delete them. Each time you do, your “Unallocated Space” will increase in size.
  4. Select your Unallocated Space and click on Next. Windows will create a partition without bothering you.
  5. The installation will occur. It will take time and your PC will restart. Setup will save your registry, install new drivers, and configure your services.
  6. You will be prompted to enter your product key. You can select the “Activate when I am Online” button to do this later, unless you have a license in front of you.
  7. Done! Windows 7 is now loaded onto your computer, which is clean, blank and nice. You can restore your old files at any time.

Mac OS X

Warning: Back Your Data Up!

  1. Reboot your Mac or Macbook. While it is restarting, press Command and R at the same time. A menu called the Recovery menu will open.
  2. Select Disk Utility and then hit continue.
  3. Select your hard drive on the left and then press Erase.
  4. Click the Format menu and select “Mac OS Extended (Journaled)”. You can rename the disk to whatever you want.


  1. Close the Disk Utility and begin the OS X install process. Reboot and connect to a network. You will then be prompted to Reinstall Mac OS X.
  2. Enter your Apple ID and password, then accept the EULA.
  3. Select the disk you just formatted.
  4. The system will install on its own. You won’t have to do a thing.

Done! As simple as A,B,C, yes? Mac OS is a lot easier to install than Windows, because the process is associated with your Apple ID.

Ubuntu (Linux GUI)

Warning – Back All Your Data Up!

An added warning is that if you are going to format and install Ubuntu from a windows PC, your Windows Recovery Disc will NOT work. Use external hard drives with files manually backed up.

  1. Download the latest Ubuntu LTS release form the website.
  2. Use a DVD burner software like k3b, cdrecord or any ISO burner to write the image to a DVD.
  3. Insert the Ubuntu DVD, then reboot and change your BIOS settings (see the Windows 7 guide above) to boot from CD/DVD.
  4. Restart your computer and wait for the Ubuntu setup to begin.
  5. Click on Install Ubuntu when prompted.
  6. Select Install Third Party Software.
  7. Click “erase disk”.
  8. Select “Install Ubuntu now”.
  9. Choose your region, language and login details when prompted.
  10. Ubuntu will install on its own, and will then prompt you to log in.

You’re done! Have fun with your new Ubuntu release! Remember to copy your old files back at some point.

You’ve Now Formatted a PC. What Now?


If everything went exactly as planned for you, give yourself a pat on the back. However, there are bound to be many of you who went through all the steps one by one and still couldn’t figure out why error messages and other issues keep popping up. Well, problems with Windows installs are the most common because of the complexity of a Windows OS. If you have been having problems with your format, here are some solutions that might help you out:

  1. Installation takes hours and keeps rebooting – Disconnect all peripherals including external drives, monitors, readers, scanners, printers, keyboard (except your standard one), and turning off your WiFi. Recheck that you have the right version – 32bit or 64bit. If everything seems fine, just wait. I took a day to format my PC at one point, so you might be unlucky enough to have the same experience.
  2. Error Messages – With a long line of numbers and text, an error message is your worst nightmare. Disable all your antivirus programs (if you’re doing an install from your current desktop) and try again. This shouldn’t happen with a clean install. If it does, redownload the upgrade and burn it again.
  3. Video and driver failures – Try downloading all your drivers through Windows Update or the Windows Device Manager. Most of the time, the cause of a driver failing is that the driver that the installation disc of the OS installed is out of date. If you have a DVD from way back when, make sure you get online and download all of the latest drivers from the manufacturer website. For laptop owners, your manufacturer usually has a driver tool that will automatically detect and upgrade your hardware drivers to the latest and most streamlined version there is.

If you have installed your new OS already and you are enjoying it, make sure you let us know if this guide helped at all. Alternatively, if you got through the installation and overcame some of the problems described above, that’s amazing too! You should let us, and any other poor souls experiencing the same problem, know how to fix it in the comments below.

Formatting your PC isn’t a difficult process, but it is one that requires a lot of caution. If you aren’t careful enough you might end up deleting a lot of the files and data that you will only realize you need at a later date. This is why it is so important that you back everything up before you do anything to your computer. Follow these instructions and take advantage of the way companies have streamlined installations, and you will have a largely problem-free formatting experience!

About the author


is a Software Developer and the main writer behind Computer Realm.

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