This appears to be a neat little command. But I'm not sure I understand the point of it.
Make sure you are logged on as your regular user account, and then open an administrator mode command prompt as above. Type the following command:
net user administrator /active:no
You don't need to log out as Administrator to disable the Administrator account. All it takes is an administrator level account, and "Administrator" is one of those. The point is, you can issue this command while still logged on as Administrator, you don't have to log out first.
What do you mean by "regular" user account? Would that be a user account with "standard" user permissions? If that's what you're referring to then this whole guide is pointless. Because I just created a standard user account on a Windows 7 Ultimate in VM just to test this. It turns out that, when you log on as a "standard" user, you cannot activate the built-in "Administrator" account with the fancy command line above. Access is denied.
C:\Users\Standard>net user Administrator /activate:yes
System error 5 has occurred.
Access is denied.
A second reason why this whole thing seems pointless is the fact that you need to have an administrator level account to activate the built-in "Administrator" account. So if you are an administrator level user already, what's the point in activating the built-in administrator account to begin with? Does the "Administrator" account have some fancy privileges that the regular admin users don't? By regular here I mean the admin account you created during installation of Windows Vista, 7, 8.x and any other admin account you may have created thereafter.
I tried doing it through the
lusrmgr.msc and got the same results. Access is denied. This was expected. So would someone care to explain the purpose of the built-in "Administrator" account then? If you need to have an administrator account already to activate it? In which case you wouldn't even bother activating the built-in account, because you can do pretty much the same (exact the same?) things with your own administrator account as with the built-in one.