Note: This article describes resetting a Windows 10 computer to factory defaults. You can read separate articles on performing something similar for  Windows 8

A system reset will remove your installed applications and rebuild the Windows 10 system files.

You can choose whether you want to keep your files or remove everything.

If you choose to keep your files, your applications will be removed, system settings will be reset, and Windows files will be rebuilt. Your data and documents will remain intact on your computer.

If you choose to remove everything, your data and documents will also be removed.

To learn what other recovery options are available to you in Windows 10, read the following article:  Windows 10 Recovery Options

If you're unable to load Windows, try performing a reset with these steps:

• Hold the '0' (zero) key as you start the computer until you reach a blue screen that says Choose an option.
• Choose Troubleshoot.
• Choose Reset your PC.
• Here you'll see multiple options that can vary depending on whether you upgraded from Windows 8 or bought a laptop that came with Windows 10. Keep my files will allow you to keep your documents. Remove everything will remove your documents and uninstall all programs, including those pre-installed by Toshiba. If you choose to remove everything, you might be given the choice of resetting all drives and partitions or resetting only the one on which Windows is installed. You may also see Reset factory settings, which resets the computer to the way it was when you bought it. Not everyone will see this selection.
• Choose the options you prefer and follow the prompts to complete the reset.

If you can successfully load Windows, you can perform a reset with these steps: :

• Open the Start Menu and select Settings.
• Select Update & security and then Recovery.
• Under Reset this PC, select Get started.
• Here you'll see multiple options that can vary depending on whether you upgraded from Windows 8 or bought a laptop that came with Windows 10. Keep my files will allow you to keep your documents. Remove everything will remove your documents and uninstall all programs, including those pre-installed by Toshiba. If you choose to remove everything, you might be given the choice of resetting all drives and partitions or resetting only the one on which Windows is installed. You may also see Reset factory settings, which resets the computer to the way it was when you bought it. Not everyone will see this selection.
• Choose the options you prefer and follow the prompts to complete the reset.

You can also watch this video explaining how to do this:  Video