What a full computer reset does and when you need one

A full reset wipes your hard drive clean and reinstalls the operating system from scratch, as if the computer just came from the factory. Everything you've installed—programs, files, photos, documents—gets deleted. Your settings, passwords, and browser history vanish. The computer returns to the state it was in before you first turned it on.

You might reset a computer because it's running slowly after years of use, malware has infected it and won't come out any other way, you're selling or giving it away and want to erase your personal data, or the operating system has become so corrupted that normal fixes don't work. A reset is also the nuclear option when a computer has so many conflicting programs and leftover files that starting fresh is faster than troubleshooting.

Before you reset, understand that this is permanent and irreversible. Files deleted during a reset cannot be recovered. If you have documents, photos, or anything else you want to keep, back them up to an external drive or cloud storage first. The reset process itself takes 30 minutes to two hours depending on your computer's speed and which operating system you're using.

Key Takeaways

  • Back up all your files to an external drive or cloud storage before starting, because a reset deletes everything on your computer permanently.
  • Windows computers reset through Settings > System > Recovery > Reset this PC, while Mac computers use System Settings > General > Transfer or Reset.
  • You will need your Microsoft account password (Windows) or Apple ID password (Mac) to complete the reset and sign back in afterward.
  • A reset takes 30 minutes to two hours and your computer will restart multiple times; do not unplug it or force shut it down during the process.
  • After the reset completes, you will need to reinstall your programs and restore your files from your backup.

How to reset a Windows computer

On Windows 10 or Windows 11, open Settings by pressing the Windows key and typing "settings," then click the app that appears. Go to System in the left sidebar, then scroll down and click Recovery. Under "Recovery options," you will 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 if you want a complete reset. If you choose "Keep my files," Windows will delete programs and settings but preserve your documents and photos—this is a lighter reset and takes less time, but it does not clean the system as thoroughly.

Next, Windows asks whether you want to reinstall from the cloud or from local files. Cloud reinstall downloads a fresh copy of Windows from Microsoft's servers—this is slower but guarantees you get the latest version. Local reinstall uses files already on your computer—this is faster but may reinstall an older version of Windows. For most people, cloud reinstall is the safer choice.

Enter your Microsoft account password when prompted. Windows will show you a summary of what will happen, then begin the reset. Your computer will restart several times. Do not turn it off, unplug it, or force it to shut down—let the process finish completely, even if it seems stuck for a few minutes. When it finishes, you will see the Windows setup screen, and you can sign in with your Microsoft account.

How to reset a Mac computer

On a Mac running macOS Monterey or newer, click the Apple menu in the top-left corner and select System Settings. Click General in the sidebar, then scroll down and click Transfer or Reset. You will see an Erase All Content and Settings button—click it.

macOS will warn you that this action cannot be undone and will delete all your files and settings. Click Continue to proceed. You will be asked to enter your Apple ID password and your Mac's login password. Enter both when prompted.

On older Macs running Big Sur or earlier, the process is different. Restart your Mac and hold down Command + R when ready after you hear the startup sound. This boots into Recovery Mode. Click Utilities in the menu bar, then Terminal. Type the command csrutil disable and press Enter to disable System Integrity Protection. Restart normally, then go to System Preferences > Erase and Reinstall. If this feels unfamiliar, contact Apple Support or a technician—the older process is more complex and easier to get wrong.

After the reset finishes, your Mac will restart and show the setup screen. Sign in with your Apple ID to complete the process.

Backing up your files before you reset

The most important step happens before you reset: back up everything you want to keep. Plug in an external hard drive or USB flash drive with enough space for all your files. On Windows, open File Explorer, select the folders you want to back up (usually Documents, Pictures, Downloads, and Desktop), right-click, and select "Send to" > your external drive. On Mac, open Finder, select your files, and drag them to the external drive.

Alternatively, use cloud storage. Upload your important files to Google Drive, OneDrive, Dropbox, or iCloud. This takes longer than copying to a local drive, but your files are safe even if your computer is stolen or damaged. Most cloud services offer free storage for a few gigabytes—enough for documents and photos, though not usually for large video files.

Write down your passwords before you reset, especially your email password and any passwords for accounts you use regularly. After the reset, you will need these to sign back in. If you use a password manager like Bitwarden or 1Password, export your passwords to a file and save it to your backup drive.

What to do after the reset is complete

Once your computer finishes resetting and you sign in, you will have a blank system with no programs installed except the operating system itself. Restore your files by plugging in your backup drive and copying your folders back to Documents, Pictures, and other locations. If you used cloud storage, sign into your cloud account and read your files.

Reinstall the programs you use regularly. read them from their official websites or from the Microsoft Store (Windows) or App Store (Mac). Do not install everything at once—add programs as you need them. This keeps your system cleaner and makes it easier to spot if something causes problems.

Update your operating system and all your programs. On Windows, go to Settings > Update & Security > Windows Update and click "Check for updates." On Mac, go to System Settings > General > Software Update. Install all available updates before you start using the computer heavily.

When to call a technician instead of resetting yourself

If your computer will not start up at all, a reset may not be possible without professional help. If you see error messages during startup or the screen stays black, the hard drive itself might be damaged. A technician can run diagnostics and tell you whether the drive can be repaired or needs replacement.

If you suspect malware or a virus is the reason you want to reset, but you cannot access Settings or Recovery options, malware may have locked you out. A technician can boot from a recovery disk and reset the computer even when the operating system is not responding.

If you have encrypted your hard drive with BitLocker (Windows) or FileVault (Mac) and you have forgotten your recovery key, you cannot reset the computer without it. Microsoft and Apple can sometimes help recover the key if you can prove ownership, but this takes time. A technician may be able to help faster.

Frequently Asked Questions

Will a reset remove viruses and malware?

A complete reset removes most malware because it deletes everything on the hard drive and reinstalls the operating system fresh. However, some advanced malware can hide in the firmware (the code that runs before the operating system loads). If malware returns after a reset, the computer may have a hardware-level infection, and you should take it to a technician.

Can I reset my computer if I forgot my password?

On Windows, you can reset without your password by using another admin account on the same computer, or by using a Microsoft account password reset if you have internet access. On Mac, you need either your login password or your Apple ID password. If you have neither, you will need to contact Apple Support or take the Mac to an authorized service provider.

How much free space do I need to reset my computer?

Windows needs at least 20 GB of free space to reset. Mac needs at least 35 GB. If your hard drive is nearly full, delete large files or programs first, or the reset may fail partway through. You can check free space in Settings (Windows) or About This Mac (Mac).

What if my computer restarts during the reset and gets stuck?

If the reset appears to hang or freeze, wait at least 10 minutes before doing anything—the process may just be slow. If nothing changes after 15 minutes, force the computer to shut down by holding the power button for 10 seconds. When it restarts, it may resume the reset automatically, or you may need to start the reset again from the beginning.

Do I need to reinstall Windows or macOS after a reset?

No. The reset process automatically reinstalls the operating system as part of the reset. You do not need to buy a new copy or read it separately. When the reset finishes, you will have a fresh, working operating system ready to use.