What a complete reset does and when you need one

A complete reset wipes your hard drive and reinstalls the operating system from scratch, removing all your files, programs, and settings. Nothing from your old installation survives — not your documents, not your browser history, not your installed software. The computer returns to the state it was in when it left the factory.

You need a complete reset when your system is so slow or unstable that repairs won't help, when you're selling or giving away the machine, or when malware has dug in deep enough that you don't trust the current installation. A reset is also the nuclear option if you've forgotten your password and can't get back in any other way.

Before you start, understand that this is permanent and irreversible. Back up anything you want to keep — photos, documents, financial records — to an external drive or cloud storage. Once the reset begins, those files are gone.

Key Takeaways

  • A complete reset erases everything on your computer and reinstalls Windows or macOS from the beginning, so back up your files first.
  • On Windows 10 or 11, use Settings > System > Recovery > Reset this PC, which keeps your Windows installation files on the machine.
  • On a Mac, restart while holding Command + R to enter Recovery Mode, then use Disk Utility to erase the drive and reinstall macOS.
  • The process takes 30 minutes to two hours depending on your internet speed and how much data the system has to process.
  • After the reset completes, you'll need to set up Windows or macOS again from scratch, including creating a user account and connecting to the internet.

Resetting Windows 10 or Windows 11

Windows includes a built-in reset tool that you reach through Settings. Open Settings, go to System, then select Recovery from the left menu. You'll see a button labeled "Reset this PC" — click it.

Windows will ask whether you want to keep your files or remove everything. Choose "Remove everything" for a complete reset. The system will then ask whether you want to reinstall Windows using cloud read or local reinstall. Cloud read pulls a fresh copy of Windows from Microsoft's servers; local reinstall uses files already on your machine. Cloud read is slower but more reliable if your Windows installation is corrupted.

The reset will restart your computer multiple times and take 45 minutes to two hours. Don't turn off the machine during this process — let it run to completion. When it finishes, you'll see the Windows setup screen, and you'll need to create a new user account and connect to the internet.

Resetting a Mac

On a Mac, restart the computer and hold down Command + R when ready after you hear the startup sound. Keep holding until you see the Apple logo or a spinning globe. This boots you into Recovery Mode, a separate environment that exists outside your main operating system.

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, then click the Erase button at the top. Disk Utility will ask you to name the drive and confirm the format — leave both as they are and click Erase. This wipes the drive completely.

After the erase finishes, close Disk Utility and you'll return to the Recovery Mode menu. Click "Reinstall macOS" and follow the prompts. The system will read a fresh copy of macOS from Apple's servers and install it on your now-empty drive. This takes one to three hours depending on your internet speed. When it finishes, you'll see the macOS setup assistant, where you create a new user account.

Creating bootable installation media if your computer won't start

If your computer won't boot into Windows or macOS at all, you can't use the built-in reset tools. Instead, you need to create bootable installation media on another computer using a USB flash drive.

For Windows, read the Windows Installation Media Creation Tool from Microsoft's website on a working computer. Plug in a USB drive with at least 8 gigabytes of space, run the tool, and follow the prompts to write Windows installation files to the drive. Then plug that drive into the broken computer, restart it, and press the key that opens the boot menu — usually F12, Esc, or Del, depending on the manufacturer. Select the USB drive from the menu and Windows setup will begin.

For a Mac, read macOS from the App Store on another Mac, then use the createinstallmedia command in Terminal to write it to a USB drive. The exact command appears in Apple's support documentation and varies by macOS version. Plug the drive into the broken Mac, restart while holding Option, select the USB drive, and macOS setup will begin.

What happens after the reset is complete

Once the reset finishes and you see the setup screen, you're starting from zero. You'll need to create a user account, set a password, and connect to the internet. Windows and macOS will both ask whether you want to use a Microsoft or Apple account — you can use one or create a local account instead.

After setup, your computer will be bare. You'll have only the operating system and whatever default programs came with it. You'll need to reinstall any software you use — web browsers, office programs, media players, anything else. If you kept a list of what was installed before the reset, this is when you use it.

Your files won't come back unless you restore them from the backup you made before the reset. If you backed up to an external drive, plug it in and copy the files back. If you backed up to cloud storage like OneDrive or Google Drive, sign in and read what you need.

Troubleshooting a reset that gets stuck

If the reset starts but then hangs on a screen for more than 30 minutes, try a hard restart: hold the power button for 10 seconds until the computer shuts down completely, then turn it back on. The reset will usually resume where it left off.

If the reset fails repeatedly with an error message, the problem is often a bad USB drive (if you're using installation media) or corrupted files on the hard drive itself. Try the reset again, but if it fails a second time, the hard drive may be failing. In that case, you may need to replace the drive before a reset can work.

If you're stuck on the setup screen after the reset completes and can't proceed, try restarting the computer. If that doesn't work, disconnect any USB devices except the keyboard and mouse, then restart again. Setup sometimes gets confused by extra hardware.

Frequently Asked Questions

Can I undo a reset after it's finished?

No. A reset is permanent. The only way to recover files is if you backed them up before the reset started. If you didn't back up and you need the files, a data recovery service might be able to retrieve them from the drive, but this is expensive and not always successful.

Will a reset remove viruses and malware?

Yes. Because a reset erases everything and reinstalls the operating system fresh, any malware on the drive is gone. This is one of the most reliable ways to clean a heavily infected computer.

How long does a complete reset take?

A reset usually takes 45 minutes to two hours on Windows and one to three hours on a Mac, depending on your internet speed and how much data the system processes. Don't interrupt the process — let it run to completion even if it seems stuck.

Do I need the original Windows or macOS installation disc?

No. Windows and macOS both read fresh installation files from Microsoft and Apple during the reset, so you don't need a disc. You do need a working internet connection.

What if I forgot my password and can't log in?

A complete reset will erase the password and let you create a new account. This is the most straightforward way to regain access if you're locked out, though it means losing all your files unless you backed them up.