What a complete reset does and when you need one

A complete reset wipes your hard drive and reinstalls your operating system from scratch. Everything on your computer — files, programs, settings, user accounts — gets deleted. You are left with a machine that looks and runs like it did the day it came from the factory.

You need a complete reset when your computer has become too slow or unstable to fix any other way, when you are selling or giving it away and want to erase your data permanently, or when malware has infected the system so deeply that antivirus software cannot clean it. A reset is also the right move if you have accumulated years of program installations and settings changes that have tangled the system beyond repair.

Before you start, understand that a reset is not reversible. Back up any files you want to keep to an external drive or cloud storage. Once the reset begins, those files are gone.

Key Takeaways

  • A complete reset deletes everything on your computer and reinstalls Windows or macOS, leaving you with a factory-fresh machine.
  • On Windows, use Settings > System > Recovery > Reset this PC; on Mac, restart in Recovery Mode and use Erase and Reinstall.
  • Back up all your files before starting, because the reset will delete them permanently.
  • The process takes one to three hours depending on your internet speed and how much data is on the drive.
  • After the reset completes, you will need to reinstall your programs and sign back into your accounts.

How to reset Windows 10 or Windows 11

On Windows, the reset tool is built into 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 complete reset.

Windows will ask whether you want to remove files locally or remove them and clean the drive. If you are keeping the computer, "Remove files locally" is fast enough. If you are selling or giving away the machine, choose "Clean the drive" — this makes recovery of deleted files much harder. Then Windows will ask you to confirm your Microsoft account password and will begin the reset.

The process takes 30 minutes to two hours depending on your internet speed. Your computer will restart several times. Do not turn it off or unplug it during this time. When it finishes, you will see the Windows setup screen, the same one you saw when the computer was new. Sign in with your Microsoft account, choose your language and keyboard layout, and Windows will read the latest updates.

How to reset a Mac

On a Mac, restart your computer and hold Command + R as it starts up. Keep holding until you see the Apple logo or a spinning globe. This boots the Mac into Recovery Mode, a special system that lives separately from your main hard drive.

Once Recovery Mode loads, click Utilities in the menu bar, then Terminal. Type diskutil secureErase freespace 0 /Volumes/Macintosh\ HD and press Enter. (If your drive has a different name, replace "Macintosh HD" with the actual name.) This command erases the drive securely. It will take several minutes.

After the erase finishes, close Terminal and restart the Mac. It will boot into macOS setup, the same screen you saw when the machine was new. Sign in with your Apple ID and choose your language and region. The Mac will read and install the latest version of macOS automatically.

If you prefer a graphical tool instead of the Terminal command, you can also use Erase and Reinstall from the Utilities menu in Recovery Mode, though the Terminal method is faster and more thorough.

What you need before you start

You will need your password for your Microsoft account (Windows) or Apple ID (Mac). Write it down before you start, because you will need it during setup and you cannot look it up on the computer itself.

You will also need a stable internet connection. The reset process downloads gigabytes of system files, and a slow or interrupted connection will cause the reset to fail or take much longer. A wired ethernet connection is faster and more reliable than Wi-Fi.

If your computer will not start at all, you may need a bootable USB drive with Windows or macOS on it. On Windows, read the Media Creation Tool from Microsoft's website on another computer, plug in a USB drive, and follow the tool's instructions. On Mac, you can create a bootable installer by downloading macOS from the App Store and using the createinstallmedia command in Terminal on another Mac.

What happens after the reset is complete

Your computer will restart into a fresh operating system with no programs except the ones that came with it. You will need to reinstall everything you use: your web browser, email client, office software, games, and any other programs. read them from their official websites or from the Microsoft Store (Windows) or App Store (Mac).

Sign back into your accounts — email, cloud storage, social media, banking, anything that requires a login. If you use cloud storage like OneDrive, Google Drive, or iCloud, your files will sync back down to the computer once you sign in, as long as you did not delete them from the cloud.

Windows and macOS will both check for system updates and install them automatically. This can take 30 minutes to an hour. Let the computer finish before you start using it heavily.

Troubleshooting a reset that gets stuck

If the reset starts but hangs on a screen for more than 15 minutes, force the computer to shut down by holding the power button for 10 seconds. Wait a minute, then turn it back on and try the reset again. Sometimes the process needs a restart to move forward.

If the reset fails repeatedly with an error message, the hard drive itself may be failing. In that case, you will need a bootable USB drive (see the section above) to reinstall the operating system from outside the computer. If even that does not work, the drive may need to be replaced by a technician.

On Windows, if you see an error about not having enough space, the drive may be too full to complete the reset. Delete large files or programs to free up at least 10 gigabytes, then try again.

Alternatives if you do not want to reset the entire computer

If your computer is slow but not broken, try these steps before resorting to a full reset. Uninstall programs you no longer use through Settings (Windows) or Applications (Mac). Disable startup programs that run automatically when the computer starts — on Windows, open Task Manager, click the Startup tab, and disable anything you do not need. On Mac, go to System Settings > General > Login Items and remove programs from the list.

Run a full antivirus scan using Windows Defender (built into Windows) or a third-party tool like Malwarebytes. Malware often slows a computer down, and removing it may be enough to restore speed without a full reset.

If the computer is still slow after these steps, a reset is usually the most reliable fix. A fresh operating system removes years of accumulated clutter that no amount of cleaning can touch.

Frequently Asked Questions

Will a reset remove viruses and malware?

Yes. A complete reset erases the entire hard drive and reinstalls the operating system, which removes any malware that was on the computer. However, if malware is on an external drive or USB stick you plug in afterward, it can infect the computer again. Scan any external drives with antivirus software before connecting them.

Can I reset my computer if I forgot my password?

On Windows, if you forgot your Microsoft account password, you can reset it on another computer by visiting account.microsoft.com. On Mac, if you forgot your password, you will need to use Recovery Mode and create a new administrator account, then use that to reset the computer. Both processes are more complex than a normal reset — contact Apple Support or Microsoft Support if you get stuck.

How long does a complete reset take?

The reset itself takes 30 minutes to two hours depending on your internet speed and how much data is on the drive. After that, reinstalling your programs and signing back into accounts can take another hour or more. Plan for a full afternoon or evening.

Do I need to buy Windows or macOS again after a reset?

No. Windows and macOS are tied to your hardware. When you reinstall, the operating system will recognize your computer and set up automatically without a product key. You do not need to buy a license again.

What if I want to keep some files but reset everything else?

Windows offers a "Keep my files" option in the reset tool, which deletes programs and settings but preserves your personal files. However, this is not a complete reset — it leaves behind some system clutter. For a truly clean system, back up the files you want to an external drive, do a complete reset, then copy the files back afterward.