Who has never dreamed of finding the Administrator password to install something or run software that does not work in limited account is actually you happen to access the connected PC as administrator by chance and simply launch a software calling "SAMInside" and click on bouton to recover "HASH" passwords. You will leave the mind of the turn for home that decrypts the password and display it clearly.

But on a family PC at home for example if your big brother or greater than you who wants to try to restrict access to PC but don't know much in IT, simply make the following manipulation and your big brother are hoodwinked. Since the account type will be displayed as "Limited" but as all user accounts including limited account will be Administrator, it will come back to have the Administrator account.

Go to Control Panel.
Click on "Administrative Tools -> Computer Management.
In the list System Tools -> Local Users and Groups -> Groups.
In the left list right click "Administrators" -> Properties.
Click to add.
Enter in the object names to select.
Type "Everyone" and click OK.

All restricted accounts now have the same rights as the Administrator account

There is just a tiny flaw is that some software check the name of the type of account regardless of the group in which the user is.