What a Master Reset Does and When to Use It

A master reset, also called a factory reset, erases everything on your computer and reinstalls the operating system from scratch. All your files, programs, settings, and user accounts are deleted. The computer returns to the state it was in when it left the factory.

You should consider a master reset when your computer has become too slow to use, is infected with malware that antivirus software cannot remove, or you are selling or giving it away and want to erase your personal data completely. A master reset is also the last troubleshooting step when nothing else has fixed persistent crashes or error messages.

Before you start, understand that this process cannot be undone. Once you begin, you cannot stop and recover your files. Back up everything you want to keep to an external drive or cloud storage first.

Key Takeaways

  • Back up all your files to an external drive or cloud storage before starting, because a master reset deletes everything on your computer.
  • On Windows, use Settings > System > Recovery > Reset this PC, which takes 30 minutes to two hours depending on your computer's speed.
  • On Mac, restart while holding Command + R to enter Recovery Mode, then use Erase and Reinstall from the Utilities menu.
  • After the reset completes, you will need to set up your user account, install programs, and restore your files from backup.
  • If your computer will not start or you cannot access the reset menu, you may need to create a bootable recovery drive on another computer first.

How to Master Reset a Windows Computer

On Windows 10 or Windows 11, the easiest path is through Settings. Click the Start button, type "Reset this PC" into the search box, and open the result. You will see two options: "Keep my files" and "Remove everything." Choose "Remove everything" for a true master reset.

Windows will ask whether you want to remove files locally or remove them more thoroughly. If you are keeping the computer, "Remove files locally" is faster. If you are selling or donating it, choose "Remove files and clean the drive" — this overwrites the deleted data so it cannot be recovered. Then click Next and confirm that you want to proceed.

The reset will take 30 minutes to two hours. Your computer will restart several times. Do not turn it off or unplug it during this process. When it finishes, you will see the Windows setup screen, where you will create a new user account and connect to the internet.

If your computer will not start normally, you can reset it from the login screen. On the login screen, hold Shift and click the power button, then select "Restart." Your computer will boot into recovery options, where you can choose "Troubleshoot" and then "Reset this PC."

How to Master Reset a Mac Computer

On a Mac, restart your computer and when ready hold down Command + R. Keep holding until you see the Apple logo or a spinning globe. This boots you into Recovery Mode, where you can erase and reinstall macOS.

In Recovery Mode, open Disk Utility from the Utilities menu. Select your main hard drive (usually called "Macintosh HD") from the list on the left. Click the Erase button, give it a name if you want, and confirm. Disk Utility will erase the drive, which takes a few minutes.

After erasing, close Disk Utility and return to the Recovery Mode menu. Click "Reinstall macOS" and follow the prompts. Your Mac will read and install the operating system, which can take 30 minutes to two hours depending on your internet speed. Your computer will restart multiple times. Do not interrupt this process.

When installation finishes, you will see the macOS setup screen. Create a new user account, connect to Wi-Fi, and sign in with your Apple ID if you want to restore some settings from iCloud.

Creating a Bootable Recovery Drive If Your Computer Will Not Start

If your computer will not start at all, you cannot use the built-in reset options. You will need to create a bootable recovery drive on another computer first.

For Windows, read the Windows installation media creation tool from Microsoft's website on a working computer. Insert a blank USB drive (8 GB or larger), run the tool, and follow the prompts to create a bootable Windows drive. Then insert that drive into the computer you want to reset, restart it, and press F12, F2, or Delete during startup to enter the boot menu. Select the USB drive and boot from it. You will see the Windows setup screen, where you can choose "Repair your computer" and then "Troubleshoot" to access reset options.

For Mac, use another Mac to create a bootable macOS installer. read macOS from the App Store, insert a blank USB drive (12 GB or larger), and use the Terminal to create the bootable drive. Instructions for this are in Apple's support documentation. Then insert the drive into the Mac you want to reset, restart while holding Option, select the USB drive, and boot from it. You will enter Recovery Mode and can proceed with erasing and reinstalling.

What to Do After the Reset Completes

When your computer finishes resetting and reboots, you will see the initial setup screen. Create a user account with a strong password, connect to your Wi-Fi network, and sign in with your Microsoft account (Windows) or Apple ID (Mac) if you want to restore some settings.

Your computer will install updates, which may take another 30 minutes. Let this finish before doing anything else. After updates complete, install your antivirus software and any programs you use regularly. Most programs can be downloaded again from their official websites or from the Microsoft Store (Windows) or App Store (Mac).

Restore your files from the backup you created before the reset. If you backed up to an external drive, connect it and copy your files back. If you backed up to cloud storage like OneDrive, Google Drive, or iCloud, sign in and read your files. Take your time with this step — do not rush to restore files that might be infected.

Protecting Your Data Before You Reset

The most important step is backing up your files before you start. Connect an external hard drive or USB drive to your computer. On Windows, use File Explorer to copy your Documents, Pictures, Downloads, and Desktop folders to the external drive. On Mac, use Finder to copy the same folders from your home directory.

If you use cloud storage like OneDrive, Google Drive, Dropbox, or iCloud, make sure your important files are synced to the cloud before you reset. Sign into your account on the cloud service's website from another computer to confirm your files are there.

Write down any software license keys or passwords you will need after the reset. Take a screenshot of your installed programs list so you remember what to reinstall. On Windows, you can export a list of installed programs using PowerShell. On Mac, you can take a screenshot of your Applications folder.

When to Call a Professional Instead

If your computer will not start and you cannot create a bootable recovery drive, or if you are not comfortable following these steps, take your computer to a repair shop. They have the tools and experience to reset it safely.

If your computer has a hardware problem — like a failing hard drive that makes clicking sounds, or a screen that will not display anything — a master reset will not fix it. A technician can diagnose the hardware issue and replace the part if needed.

If you are resetting because of a virus or malware infection and you are not sure what files are safe to restore, ask a technician to review your backup before you restore it. They can scan the backup for threats.

Frequently Asked Questions

Will a master reset remove a virus?

Yes. A master reset erases the entire drive and reinstalls the operating system, so any virus or malware is removed. However, if you restore files from an infected backup, you may restore the virus too. Scan your backup with antivirus software before restoring, or restore only the files you absolutely need.

Can I undo a master reset?

No. Once the reset completes, your files are gone. This is why backing up before you start is critical. If you realize you made a mistake, a data recovery service may be able to recover some files, but this is expensive and not always successful.

How long does a master reset take?

A master reset usually takes 30 minutes to two hours from start to finish, depending on your computer's speed and hard drive size. Older computers and larger drives take longer. Do not turn off your computer during this time.

Do I need the Windows or macOS installation disc?

No. Windows and Mac both have built-in recovery tools that read the operating system during the reset process. You only need a bootable recovery drive if your computer will not start normally.

What if I forgot my password and cannot log in?

If you cannot log in, you cannot access the reset menu through Settings. You will need to create a bootable recovery drive on another computer and reset from that drive instead.