Actually there is and its a hidden account. To unhide do the following:
First, open an elevated command prompt by typing cmd into the Search box
on the Start menu, right-clicking the command prompt icon that appears at
the top of the Start menu, then selecting Run as administrator.
Then enter this command and press Enter:
Net user administrator /active:yes
To undo or hide the account:
Net user administrator /active:no
The major caveat is this is a Super Admin account, and should be used only
for admin duties, it should never be used for day to day usage.
Dan