If you want to disable any acct, including the hidden ones, the best way to work with these accts is to use mmc.

1) go to start --> run and type in "mmc" without the quotes and hit enter
2) go to file --> add remove snap-in or hit cntrl+m and a new window will pop up
3) click on the button that says add and another new window will pop up
4) scroll down through the list until you see "local users and groups"
5) Double click and then another window pops up. Leave the radio button highlighted for local machine and click on Finish
6) Click on Close and then OK...you should be to the console root page then and ready to play with the settings.
NOTE: Be careful what you do as any changes made here overide everything else in the system and may not be reverisble.....
7) double click on the file in the right pane and you will see all the accounts (including hidden ones)
Have Phun and Be safe