Make sure you backup files that you want to save. Select Start > Settings > Update & Security > Backup > Add a drive , and then choose an external drive. After you've backed up the info you need, select Start > Settings > Update and security > Recovery . Under Reset this PC , select Get started , and then follow the instructions on the screen. Resetting your device removes your files, settings, and apps, then re installs Windows. Remove a device from your Microsoft account After you've backed up and reset your device, you should remove it from your Microsoft account. Here's how: Go to https://account.microsoft.com/devices , sign in, and find the device you want to remove. Select Show details to see info for that device. Under your device's name, select More actions > Remove . Review your device details, select the box for I'm ready to remove this d