From an administrator’s point of view lots of things that can be altered in a way that make the computer or part of it unusable for that user. This can happen in a family that is sharing a computer as well if someone who is not that proficient with computers changes certain settings all the time or likes to “tweak” settings to optimize the computer.

There is a very easy way to prevent users of a computer to change the settings in their user profile permanently. They can still change everything but those settings will only be temporarily changed.

This can be done by changing the NTUSER.DAT file into a NTUSER.MAN file for that user. Windows automatically recognizes the profile as a mandatory profile from then on. The NTUSER.DAT file is located in the user’s %USERNAME% directory, usually c:\documents and settings\username\. This should work on all Windows NT operating systems including Windows XP and Windows Vista.

Here is how this is done: Start the Windows Registry with the shortcut Windows R, typing regedit and pressing enter. Now mark the HKEY_Users folder in the Registry and click on File > Load Hive afterwards. The default directory that opens is the directory of the current user. Navigate to the user directory of the user that you want to make changes for, all available ones are listed in Document and Settings.

Enter that folder and look for the file ntuser.dat. That file is hidden, if you can’t locate it change the folder settings so that you can see hidden files and folders in Windows. A double-click on the file loads the Registry hive as a subfolder of HKEY_Users with the name that you have selected after clicking on the ntusers.dat file.