With Windows Startup Settings (which used to be called "Advanced boot options") you can start Windows in different advanced troubleshooting modes to help you find and fix problems on your PC.
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 lower-right corner of the screen, move the mouse pointer up, click Settings, and then click Change PC settings.)
Under PC settings, tap or click Update and recovery, and then tap or click Recovery.
Under Advanced startup, tap or click Restart now.
Once your PC restarts, on the Choose an option screen, tap or click Troubleshoot.
If you don't see the Startup Settings option, tap or click Advanced options.
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.
If you can't start (boot) your PC, follow these steps to get to the Windows Recovery Environment. You'll need to connect a keyboard before you begin.
Do one of the following, depending on whether you have installation media (such as a DVD or USB flash drive):
If you have installation media for Windows 8.1, start (or boot) your computer from the installation media. Insert the DVD or USB flash drive and restart your computer. If you see a message asking you to “Press any key to boot from DVD,” do so. If you don’t see the message, you might need to change the boot order in your computer's BIOS settings so that it first starts from the DVD or USB. When you see the Install Windows page, tap or click Repair your computer to start the Windows Recovery Environment.
If you don’t have installation media, use the power button to restart your computer three times. This will start the Windows Recovery Environment.
In the Windows Recovery Environment, on the Choose an option screen, tap or click Troubleshoot.
If you don't see Startup Settings, tap or click Advanced options, and then tap or click Startup Settings.
Tap or click Restart, and then wait while your computer restarts.
On the Startup Settings screen, choose an option.
Sign in to your computer 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 pros). For more info, go to the Microsoft TechNet website for IT pros.
If you're using BitLocker, you'll need to suspend it before you can get to Windows Startup Settings. If you're using Windows RT 8.1, you might be asked to enter your Device Encryption recovery key to get to the Startup settings.
Starts Windows in an advanced troubleshooting mode intended for IT pros and system admins.
Creates a file, ntbtlog.txt, that lists all the drivers that are installed during startup and that might be useful for advanced troubleshooting.
Starts Windows using your current video driver and using low resolution and refresh rate settings. You can use this mode to reset your display settings.
If you have a problem with your PC, you can troubleshoot by starting it in safe mode. Safe mode starts Windows with a minimal set of drivers and services. If a problem doesn't reappear when you start your PC in safe mode, you can eliminate the default settings and basic device drivers and services as possible causes. There are three different safe mode options:
Enable Safe Mode: Starts Windows with a minimal set of drivers and services.
Enable Safe Mode with Networking: Starts Windows in safe mode and includes the network drivers and services needed to access the Internet or other computers on your network.
Enable Safe Mode with Command Prompt: Starts Windows in safe mode with a Command Prompt window instead of the usual Windows interface. This option is intended for IT pros and system admins.
If the problem doesn't occur when you restart your PC in safe mode, you can be confident that the basic settings, files, and drivers in Windows aren't causing the problem. Then, use the process of elimination to help you find the cause of the problem. Try starting all of the apps on your desktop that you commonly use one by one (including the apps in your Startup folder) to see if a specific app might be causing the problem. If one of the apps is causing the problem, uninstall it or contact the software publisher. If the problem appears while in safe mode, or you still can't find the problem, you can try refreshing or resetting your PC. For more info, see How to refresh, reset, or restore your PC.
Allows drivers containing improper signatures to be installed.
Prevents the early launch antimalware driver from starting, allowing drivers that might contain malware to be installed.
Prevents Windows from automatically restarting if an error causes Windows to fail. Choose this option only if Windows is stuck in a loop where Windows fails, tries to restart, and fails again repeatedly.
Starts Windows domain controller running Active Directory so that the directory service can be restored. This option is intended for IT pros and system admins.