Back up before you do anything else
Formatting a laptop is not reversible. Whichever method you use, copy anything you want to keep, documents, photos, and downloaded files, to an external drive or a cloud service first. If your Windows drive is encrypted with BitLocker, locate your recovery key beforehand in case it's requested partway through. If your Mac is signed into iCloud, make sure anything not already synced is backed up separately, since Erase Assistant also signs you out of iCloud and removes Find My from the device.
How do I format a Windows laptop?
- Open Settings and go to System > Recovery.
- Under Reset this PC, select Get started.
- Choose Keep my files to reinstall Windows while keeping personal files, or Remove everything to erase personal files as well.
- Choose Cloud download or Local reinstall when prompted.
- Follow the remaining on-screen instructions to complete the reset.
Per Microsoft's own support documentation, Keep my files removes apps, drivers, and settings changes you made but leaves personal files in place, while Remove everything also deletes personal files, taking the laptop closer to its factory state.
How do I erase a Mac with Erase Assistant?
- Choose Apple menu > System Settings.
- Click General in the sidebar, then click Transfer or Reset.
- Select Erase All Content and Settings and follow the prompts, entering your Apple Account details if asked.
Apple's own support guidance notes that Erase Assistant signs you out of iCloud and other Apple services, turns off Find My and Activation Lock, and erases your content, settings, and installed apps. It's available on Mac computers with Apple silicon or the Apple T2 Security Chip, running macOS Monterey or later; older Intel Macs without a T2 chip need the Disk Utility method instead.
How do I erase a Mac using Disk Utility in macOS Recovery?
- Start up your Mac into macOS Recovery (shut down, then start up while holding the appropriate key combination for your Mac, or use the Recovery options for Apple silicon Macs).
- From the list of utilities, select Disk Utility, then click Continue.
- Select Macintosh HD (or your startup disk's name) in the sidebar and click Erase in the toolbar.
- Give it a name and choose a format, then confirm.
This full wipe-and-reinstall route is useful when Erase Assistant isn't available on your Mac, or when you want a clean disk before reinstalling macOS from Recovery afterward.
People also ask
What is the difference between Keep my files and Remove everything when resetting a Windows laptop?
Keep my files reinstalls Windows and removes apps, drivers and settings, but leaves personal files in place. Remove everything also deletes personal files. Back up important data either way, since app data and settings are lost in both cases.
How do I fully erase a Mac before selling or giving it away?
Use Erase Assistant: Apple menu > System Settings > General > Transfer or Reset > Erase All Content and Settings. It's available on Apple silicon or T2-chip Macs running macOS Monterey or later.
Do I need to back up my laptop before formatting it?
Yes, formatting is not reversible on Windows or Mac. Back up files to an external drive or cloud storage first, and keep your BitLocker recovery key handy on Windows if your drive is encrypted.