How to enable the F8 key to start Safe Mode in Windows 8

With Windows 8, Microsoft updated the standard boot menu policy to include the new Modern UI recovery environment. They also reduced the amount of time Windows waits for an interrupt in the boot sequence to nearly nothing. To get that classic F8 behavior back we need to restore the legacy boot menu policy  

When Microsoft designed Windows 8 they optimized the boot process in order to make Windows load faster. While this was a welcome change from previous Windows versions, the faster boot time made it impossible to use the F8 key to load the Boot Menu for booting into Safe Mode. If you prefer the convenience of being able to boot into Safe Mode in Windows 8 by pressing the F8 key at start up over the faster boot process, you can re-enable the F8 key and have it work just like it always has.

What You Should Do :

1 – Press the Windows+X key combination to open the Power User Tasks Menu. Elevated Command Prompt / Command Prompt Run as administrator

2 – Click on Command Prompt (Admin).

3 – Type the following line at the command prompt and then press the Enter key:

bcdedit /set 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 these 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 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.