Shutdown Client via cmd and enter boot menu

I'm trying to enter the boot-menu on my Lenovo P3 Tower, but it boots too fast for me to click the buttons.

I tried to access the boot-menu via cmd, by entering the prompt:

shutdown.exe /r /f /fw /t 000

The problem I have is:

The client doesnt have the required permission. (1314)

I'm trying it as an admin.

The shutdown and restart works, but the '/fw' part doesn't.

Does anyone have a clue on how to resolve this issue?

Thanks in advance.