To enable the Windows 7 administrator account

To enable the Windows 7 administrator account:

net user administrator /active:yes

To disable the Windows 7 administrator account:

net user administrator /active:no

To change the password of the Windows 7 administrator account:

Net user administrator password

An alternative would be to enable or disable the Windows 7 administrator account using the Local Security Policy option. You can open the Local Security Policy by launching secpol.msc from the run box.

You find the option under Local Policies-> Security Options. Just change the setting Accounts: Administrator account by double-clicking the entry.