Enable the F8 key to start Safe Mode in Windows 8

To enable the F8 key in Windows 8 you will first need to open an elevated command prompt. To do this you can follow the steps in this tutorial:

-->To open an elevated command prompt, use the Windows+X keyboard combination ( + ) to open the Power User Tasks menu.

When the menu is open click on the Command Prompt (Admin) menu option. If you use receive a User Account Control prompt, please allow it to continue. You will now see an elevated command prompt as shown below.

 You can now use the command prompt by typing the commands you wish to execute and then pressing Enter on your keyboard.

When the elevated command prompt is open you will be at the C:\Windows\System32> prompt. To enable F8 in Windows 8 you need to type the following in the command prompt and then press the Enter key.

bcdedit /set {default} bootmenupolicy legacy

Once you enter the above text, your command prompt should look like:

Once the command has been enter as shown above, press the Enter key on your keyboard. If you entered the command correctly, Windows will report that the "The operation completed successfully.". You now need to restart your computer for the change to go into effect. With this settings configured, you can now press F8 while Windows 8 starts in order to access Safe Mode and other Advanced Boot options.

If you would like to disable the F8 key and go back to the original Windows 8 setting you can open an elevated command prompt and enter the following command:

bcdedit /set {default} bootmenupolicy standard

Once you enter the above command, press Enter on your keyboard. If you entered the command correctly, Windows will report that the "The operation completed successfully." and you should now restart your computer. The F8 key will now be disabled in Windows 8.