Reader of iGuRu.gr Christoforos Androglou shows us a Windows bug that allows you to bypass the time constraint that can be set by the parental control service. 
Let's see how it works:
When user time expires, the Windows they throw a blue screen asking for an administrator code to give extra time.
From this point you select restart or shutdown and just before the screen closes (it will still say that it is shutting down / restarting) press the combination of the 3 ctrl-alt-del keys together to open the management tasks.
There is a timing issue somewhere here, as Christopher mentions, as it needs to succeed about 1 second before the output is complete. Sometimes it opens directly and the surface work, but others should be started from RUN by following the path File-New task or File-Run new task. Please type explorer and press enter.
Privileges and access level are dependent on user access levels (admin or normal user).
Watch this video created by Christoforos for iGuRu.gr
https://www.youtube.com/watch?v=PFoTI6PgGug
