Windows update disabled

Well, they've all been uninstalled now.

I've run this:

reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /v AUOptions /t REG_DWORD /d 0 /f

which seems to have applied the registry value but running this:

sc config wuauserv start= auto

Gives this:

[SC] ChangeServiceConfig FAILED 5:

Access is denied.

I need to change permissions somehow but no idea how to do that.