A factory reset erases your personal files, accounts, and settings, but leaves the operating system and built-in apps intact

A factory reset wipes your device back to the state it left the manufacturer. This means your photos, documents, emails, browsing history, saved passwords, and any programs you installed are gone. Your device's core software — the operating system that makes it run — stays in place. So does the software that came pre-installed, like the camera app or calculator.

The confusion happens because "everything" sounds absolute. A factory reset removes everything you added or changed, not everything on the device. If you sell a used phone or laptop, a factory reset makes it safe to hand over because the new owner won't see your data. But the device still works the moment they turn it on.

Key Takeaways

  • A factory reset removes all your personal files, photos, emails, passwords, and installed programs, but the operating system and pre-installed apps remain.
  • On Windows, macOS, iPhone, and Android, a factory reset is reversible only if you have a backup made before the reset — the reset itself cannot be undone.
  • You should back up your files before resetting if you want to keep anything, because the reset process does not ask you to confirm what you're deleting.
  • A factory reset does not remove malware or viruses in most cases; antivirus software or professional help is needed for that.

What actually gets deleted

Your personal data goes: photos, videos, documents, spreadsheets, downloaded files, email messages, browser bookmarks, saved passwords, and your login credentials for websites and apps. Any program you installed — whether from the app store or downloaded directly — is removed. Your customizations disappear too: desktop backgrounds, theme colors, keyboard shortcuts, and the way you arranged your files.

On a Windows computer, this includes files in your Documents, Downloads, Desktop, and Pictures folders, plus anything in cloud services like OneDrive if you chose to sync them locally. On a Mac, it includes your Home folder. On an iPhone or Android phone, it includes everything except the core iOS or Android system itself.

What stays on the device

The operating system remains: Windows, macOS, iOS, or Android. The built-in apps that came with your device stay too — on Windows, that's Notepad, Calculator, and Settings; on Mac, it's Safari, Mail, and Photos; on iPhone, it's the Phone app, Messages, and Camera; on Android, it depends on the manufacturer but usually includes Google apps like Gmail and Maps.

Firmware — the low-level software that controls your hardware — also stays. This is why a factory reset does not turn your device into a brick. The device boots up and works when ready after the reset completes, even though it has no user accounts or personal files.

How to back up before you reset

On Windows, use File History or System Image. File History backs up your Documents, Pictures, and other personal folders to an external drive or network location. To turn it on, go to Settings > System > Storage > Advanced storage options > Backup options, then choose an external drive. System Image creates a complete copy of your entire drive, which takes longer but lets you restore everything exactly as it was.

On Mac, use Time Machine. Plug in an external drive, go to System Settings > General > Time Machine, and click "Set Up Time Machine." Choose your external drive and let it run. Time Machine backs up continuously after the first backup finishes.

On iPhone, go to Settings > [Your Name] > iCloud > iCloud Backup and turn it on, or connect to a computer with Finder (macOS Catalina and later) or iTunes (older versions) and click "Back Up Now." On Android, go to Settings > Google > Manage your Google Account > Backup and turn on "Backup by Google One," or use your manufacturer's backup tool if available.

Factory reset does not remove malware

A common misconception is that a factory reset cleans malware or viruses from your device. It does not. If malware infected your system files or firmware, it may survive the reset. If it only infected your personal files or installed programs, those get deleted, but the malware may have already done its damage — stolen passwords, copied files, or modified system settings before the reset.

If you suspect malware, run antivirus software before you reset, or reset and then run antivirus after. Some antivirus programs can scan and remove threats without a reset. If your device is severely compromised, professional repair may be safer than attempting a reset yourself.

The reset process on each device type

On Windows 10 or 11, go to Settings > System > Recovery and click "Reset this PC." Choose "Remove everything" and select whether to remove files locally or cloud-based. The process takes 30 minutes to an hour and your device restarts several times.

On Mac, restart and hold Command + R to enter Recovery Mode, then go to Utilities > Erase Disk. Select your drive, choose a file system format (APFS for newer Macs, Mac OS Extended for older ones), and click Erase. Then reinstall macOS from the same Recovery Mode menu.

On iPhone, go to Settings > General > Transfer or Reset > Erase All Content and Settings. You'll need your Apple ID password. The process takes 5 to 10 minutes.

On Android, go to Settings > System > Reset options > Erase all data (Factory reset). The exact path varies by manufacturer, but the name is usually similar. You may need your Google account password. The process takes 10 to 20 minutes.

What happens after the reset

Your device restarts and shows the initial setup screen, as if it just came from the store. You create a new user account (or sign in with an existing one on phones), choose your language and region, and connect to Wi-Fi. From there, you can restore from a backup if you made one, or start fresh.

If you're selling or giving away the device, stop after the initial setup and hand it over. The new owner will complete their own setup with their own account. If you're keeping it, restore your backup or reinstall your programs and files manually.

Frequently Asked Questions

Can I undo a factory reset?

Only if you have a backup made before the reset. The reset itself cannot be reversed — once it completes, your personal files are gone. That's why backing up is essential. If you have a backup, you can restore it when ready after the reset finishes.

Will a factory reset make my old device faster?

Temporarily, yes. Removing years of installed programs, cached files, and settings clears out clutter. But if your device is slow because of hardware age — an old processor or full storage — a reset won't fix that. The slowness usually returns as you reinstall programs and files.

Do I need to factory reset before selling my device?

Yes. A factory reset removes your personal files, accounts, and passwords, making it safe to hand over. Without it, the new owner could access your email, photos, and saved login information. Always reset before selling, trading in, or giving away any device.

What if my device won't turn on — can I still factory reset it?

Yes, but the method depends on your device. On most phones, you can hold specific button combinations (Power + Volume Down on Android, Power + Home on older iPhones) to enter recovery mode and reset from there. On computers, you may need to boot from a recovery drive or USB. If you're unsure, look up the specific steps for your device model.

Does factory reset remove my Microsoft or Apple account?

The reset removes your account from the device, but not the account itself. Your Microsoft or Apple account still exists online. After the reset, you can sign back in with the same credentials on the same device or a different one.