What "completely wipe" means and why you might do it

Completely wiping your computer means erasing everything on the hard drive or solid-state drive — every file, every program, every setting — and then reinstalling the operating system from scratch. When you do this, the computer boots up as if it just left the factory, with no trace of your old files, passwords, browsing history, or installed software.

People do this for several reasons: selling or giving away the computer, removing malware that antivirus software cannot catch, fixing performance problems that a fresh start might solve, or simply starting over after years of accumulated clutter. A wipe is more thorough than a factory reset on many computers, because it overwrites the drive itself rather than just hiding old data.

The process takes different forms depending on whether you use Windows, macOS, or Linux, and whether you want to keep the same operating system or switch to a different one. The steps also differ if your computer uses an older hard drive or a newer solid-state drive.

Key Takeaways

  • Back up any files you want to keep before you start, because wiping erases everything on the drive permanently.
  • Windows computers can be wiped through Settings > System > Recovery > Reset this PC, or by booting from a Windows installation USB drive.
  • macOS computers use Erase and Reinstall through System Settings, or Recovery Mode if you cannot boot normally.
  • You will need the product key or account login for your operating system to reinstall it after the wipe is complete.
  • The entire process usually takes one to three hours depending on drive size and internet speed.

Back up your files before you start

Before you wipe anything, move every file you want to keep to an external drive, cloud storage, or another computer. This is the step people skip and then regret. Once the wipe begins, recovery is possible but difficult and expensive — it is far simpler to copy your files first.

Use an external USB drive, a portable hard drive, or a cloud service like Google Drive, OneDrive, or Dropbox. Copy your Documents, Pictures, Downloads, Desktop, and any other folders where you store work. If you use email, export your messages and contacts from your email client before you wipe — most email services keep messages on their servers, but local copies and settings will be gone.

Check that your backup actually contains what you think it does by opening a few files on the external drive. This takes five minutes and prevents the sinking feeling of discovering your backup is empty.

Wiping a Windows computer

Windows offers two main routes: the built-in reset tool, or a manual wipe using installation media. The built-in tool is faster and works for most people.

Using the built-in reset tool: Go to Settings > System > Recovery. Click "Reset this PC" and choose "Remove everything." Windows will ask whether you want to remove files only or also clean the drive — choose "Remove files and clean the drive" for a more thorough wipe. Select "Cloud download" to download a fresh copy of Windows from Microsoft's servers, or "Local reinstall" if you want to use the copy already on your computer. The process takes 30 minutes to two hours depending on your internet speed and drive size.

Using installation media: If your computer will not boot into Windows, or if you want more control over the process, create a bootable USB drive with Windows installation files. On another computer, download the Windows installation tool from Microsoft's website, plug in a blank USB drive (8 GB or larger), and follow the tool's steps to create the installation media. Then plug the USB drive into the computer you want to wipe, restart it, and press the key that opens the boot menu — usually F12, Esc, or Del, depending on your computer's manufacturer. Select the USB drive, choose "Install now," and when prompted, select "Custom: Install Windows only" and delete all partitions on the drive. Windows will then install fresh onto the empty drive.

After either method completes, you will see the Windows setup screen asking for your language, time zone, and Microsoft account. Sign in with the account you used to purchase Windows, or enter your product key if prompted. Your computer will then download and install updates, which can take another 30 minutes to an hour.

Wiping a macOS computer

On a Mac, the process depends on whether your computer uses Apple silicon (M1, M2, M3 chips) or an Intel processor, because the steps differ slightly.

On Apple silicon Macs: Restart your computer and hold down the power button until "Loading startup options" appears. Click "Options," then "Continue," and sign in with your Apple ID. Open Disk Utility from the Utilities window, select your main drive (usually called "Macintosh HD"), and click "Erase." Choose a name for the drive, select APFS as the format, and click "Erase" again. Once that completes, close Disk Utility and click "Reinstall macOS." Follow the prompts to download and install a fresh copy of macOS. This takes one to three hours depending on your internet speed.

On Intel Macs: Restart and hold Command + R to enter Recovery Mode. Open Disk Utility, select your main drive, and click "Erase." Choose a name and format (APFS for newer Macs, Mac OS Extended for older ones), then erase. Close Disk Utility and select "Reinstall macOS" from the Utilities menu. Sign in with your Apple ID and follow the installation prompts.

After macOS reinstalls, you will see the setup assistant asking for your language, time zone, and Apple ID. Sign in with the account you used to purchase your Mac. The system will then download and install updates.

What to expect during and after the wipe

The wipe itself usually takes 15 to 45 minutes, depending on your drive size and whether the system is overwriting every sector (which is slower but more secure). During this time, your screen may go black, show a progress bar, or display status messages. Do not turn off the computer — let it finish.

After the wipe completes and the operating system reinstalls, your computer will restart and ask you to set it up as if it were brand new. You will need to sign in with your Microsoft account (Windows) or Apple ID (macOS), choose your language and time zone, and decide whether to use recommended settings or customize them. This setup usually takes 10 to 30 minutes.

Once setup finishes, your computer will download and install updates, which can take another 30 minutes to an hour depending on your internet connection. During this time, your computer may restart several times — this is normal. Do not turn it off.

After updates finish, your computer is completely wiped and ready to use. You can then restore your backed-up files, reinstall your programs, and sign into your accounts.

Selling or giving away your computer after a wipe

A complete wipe removes your personal data, but the new owner will still need to activate the operating system. On Windows, they will need either a product key or a Microsoft account to sign in. On a Mac, they will need to sign in with an Apple ID during setup.

Before you hand over the computer, make sure you have removed it from your own accounts. On Windows, go to Settings > Accounts > Your info and note your account name, then sign out. On a Mac, go to System Settings > General > Transfer or Reset, click "Erase All Content and Settings," and follow the prompts — this removes your Apple ID from the computer so the new owner can set it up with their own.

If you are selling the computer, include the product key (Windows) or let the buyer know they will need their own Apple ID (Mac). If you are giving it away, you may want to include the product key or account information so the new owner can activate the system without buying a new license.

Troubleshooting common problems

The computer will not boot into the operating system: If your computer gets stuck on a black screen or shows error messages during the wipe, try restarting it and booting from your installation media again. If you are using a USB drive, make sure it is plugged in before you restart, and press the boot menu key (usually F12, Esc, or Del) immediately after the computer starts.

The wipe process is taking much longer than expected: Wiping a very large drive can take several hours. If your computer has been running for more than four hours, it may be stuck. Try restarting and beginning again, or try the alternative method (built-in reset tool instead of installation media, or vice versa).

You forgot your password and cannot sign in after the wipe: If you cannot remember your Microsoft account password, go to the Windows login screen, click "I forgot my password," and follow the recovery steps. If you cannot remember your Apple ID password, restart your Mac and hold Command + Q during setup to skip signing in, then sign in later through System Settings.

Your computer has a very old hard drive and the wipe is extremely slow: Older mechanical hard drives are much slower than solid-state drives. The wipe may take six hours or more. If possible, consider upgrading to an SSD before wiping, which will also make your computer faster after the wipe is complete.

Frequently Asked Questions

Will a wipe remove viruses and malware?

Yes. A complete wipe erases everything on the drive, including any malware. However, if the malware is on a USB drive or external device you plug back in, it can return. After wiping, scan any external drives with antivirus software before connecting them to your newly wiped computer.

Can I recover files after I have wiped the computer?

Recovery is possible but difficult and expensive. Data recovery services can sometimes retrieve files from a wiped drive, but they cost hundreds of dollars. This is why backing up before you wipe is so important — it is far cheaper and faster than trying to recover files afterward.

Do I need the Windows or macOS installation disc?

No. You can download Windows and macOS for free from Microsoft and Apple respectively. You only need a USB drive and another computer with internet access to create the installation media. You will need a product key or account login to activate the system after installation.

What if I want to switch from Windows to macOS or Linux?

You can install any operating system on most computers, but compatibility varies. Macs can only run macOS. Windows computers can run Linux, but switching to macOS requires special software and is not officially supported. If you want to switch operating systems, research whether your specific computer model supports the new system before you wipe.

How long does a complete wipe take?

The entire process — backing up files, wiping the drive, reinstalling the operating system, and downloading updates — usually takes one to three hours. Older computers with mechanical hard drives may take longer. The wipe itself is typically 15 to 45 minutes, but the operating system installation and updates can add one to two hours.