How to Enable F8 Menu in Win 8 and win 10 using command

By default legacy boot menu is not enable in windows 8 and windows 10. So, by pressing F8 key at boot time you cannot get legacy boot menu for choosing safe mode or any troubleshooting option. For this, you have to enable legacy boot menu manually after installing windows 8 or windows 10. If you have not enabled legacy boot menu policy from default standard boot menu policy in windows 8 and windows 10,
Type:bcdedit /set {default} bootmenupolicy legacy