Boot Into Safe Mode / Command Prompt

Open a command prompt with administrative privileges.

Safe Mode:
bcdedit /set {default} safeboot minimal

Safe Mode with Networking:
bcdedit /set {default} safeboot network

Safe Mode with Command Prompt:
bcdedit /set {default} safeboot minimal
bcdedit /set {default} safebootalternateshell yes

You need to remove the bcdedit value to prevent the PC from continually booting into safe mode.
bcdedit /deletevalue {default} safeboot