Windows Startup Settings (including safe mode)
Applies to Windows 8.1, Windows RT 8.1
With the Windows Startup Settings screen (formerly advanced boot options) you can start Windows in different advanced troubleshooting modes so you can find and fix problems on your PC. In previous versions of Windows, you could get to this screen by pressing F8 before Windows started up. Windows 8 PCs start up quickly so there’s not enough time to press F8.
There are two ways to get to the Windows Startup Settings screen in Windows 8 :
If you’re not signed in to Windows, tap or click the power icon from the sign-in screen, hold Shift, and then tap or click Restart
Or, if you’re already signed in:
Swipe in from the right edge of the screen, tap Settings, and then tap Change PC settings.
(If you’re using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, click Settings, and then click Change PC settings.)
Under PC settings, tap or click General.
Under Advanced startup, tap or click Restart now.
On the Choose an option screen, tap or click Troubleshoot.
Tap or click Startup Settings.
Tap or click Restart.
On the Startup Settings screen, choose the startup setting you want.
Sign in to your PC with a user account that has administrator rights.
Some options, such as safe mode, start Windows in a limited state where only essential programs are started. Other options start Windows with advanced features (typically used by system admins and IT professionals). For more info, go to the Microsoft website for IT professionals.
via Windows Startup Settings (including safe mode) – Microsoft Windows Help.