Protecting Windows NT Machines

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Environment: Windows NT 4.0 (Server or Workstation)

Windows NT security makes it possible to lock down a desktop so a given user has access to only one or a few specific programs. On a public kiosk computer, it is often important that user access be restricted. This article explains the steps that need to be taken to implement this before you start please read the IMPORTANT notice.

IMPORTANT: This article contains information about editing the Windows registry. Before you edit the registry, you should first make a backup copy of the registry files (System.dat and User.dat). Both are hidden files in the Windows folder. Do not run the sample .reg file which contains all the specified registry entries as a demonstration or test because doing this will disable the menus of the demonstrator and might not give him access to remove the entries also. It is advised that for demonstration, make only one entry at once. Unsolicited changes in registry might damage the system functionality in which cases author can not be held responsible.

Windows always works on its Registry entries which are stored some hidden .dat files usually the system.dat and user.dat in widows directory. It can be viewed as the settings for the individual user determining his environment in Windows NT user session. It is found that these settings or registry entries play a key role while deciding the access to individual user on any Windows NT machine. Whenever the user loggs in, Windows fetches all the settings from files, and loads it in the memory. So the user settings are stored with your windows explorer which works like shell for your Windows NT session. For making the registry entries, you can either go to RUN menu and run regedit.exe or regedt32.exe. This will open a windows similar to Windows explorer. There are five by default major categories viz. HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS,HKEY_CURRENT_CONFIG which are used for the basic functionality of the Registry and Windows security.

You can browse through and make the entries at right places.Windows also specifies a format which goes in .reg file (see the sample code), which can be run from any location. This .reg file can be edited using a simple notepad also. In this format, specify the REGEDIT4 first, to tell the version of editing utility, then you have to specify the absolute path in square brackets where this registry entry will go for example [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies] you can specify multiple paths also where the settings will be stored followed by the name of the entries which have to be made are written as

"NameOfEntry"=DataType:ValueOfTheEntry

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For restricting the access, following are the names of the entries/keys and their functionality at [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies]

Key Name	Functionality	Data Type	Value
NoFind	Removes Find command from Start menu.	dword	00000095
NoFolderOptions	Removes the Folder Options menu item from the Settings	dword	00000001
NoRecentDocsMenu	Removes the Documents command from the Start menu.	dword	00000001
NoDesktop	Hide all items on desktop.	dword	00000001
NoRun	Removes Run command from Start menu	dword	00000001
NoLogOff	Disables the logoff options	dword	00000001
NoClose	Disables Shut Down command.	dword	00000001
NoNetHood	Hides Network Neighborhood.	dword	00000001
NoDrives	Hides drives in My Computer.	dword	00000000
	To give access to only drive C	dword	fbffff03
	To give access to drives C and D	dword	f3ffff03
	To give access to drives A to F	dword	c0ffff03
NoTrayContextMenu	Removes context menus for tray including the start button, tab control, and clock.	dword	00000001
NoSetFolders	Remove folders from Settings/Start menu	dword	00000001
NoSetTaskbar	Remove Taskbar from Settings/Start menu.	dword	00000001
NoFavoritesMenu	Removes the Favorites folder from the Start menu.	dword	00000001
NoSaveSettings	Does not save settings at exit.	dword	00000001
NoDriveTypeAutoRun	Prevents CD-ROM drive from running automatically.	dword	00000001
NoViewContextMenu	Removes the context menu when you right click the desktop, or when you right click explorer in the results pane.	dword	00000001
NoFolderOptions	Removes the Folder Options menu item from the Settings	dword	00000001

Note : NoRecentDocsMenu and NoRecentDocsHistory requires Active Desktop to be installed; otherwise they do not work

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At the place [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]

Key Name	Functionality	Data Type	Value
DisableLockWorkstation	Disables the Lock workstation option from menu	dword	00000001
DisableTaskMgr	Disables the Task Manager	dword	00000001
DisableChangePassword	Disables the password change option	dword	00000001

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Copy the following source in notepad and save it as .reg file

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REGEDIT4 

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies] 

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer] 

"NoDriveTypeAutoRun"=dword:00000095 
"NoFind"=dword:00000001 
"NoFolderOptions"=dword:00000001 
"NoDesktopUpdate"=dword:00000001 
"NoFavoritesMenu"=dword:00000001 
"NoRecentDocsMenu"=dword:00000001 
"NoSetActiveDesktop"=dword:00000001 
"NoDesktop"=dword:00000001 
"NoSetFolders"=dword:00000001 
"NoSetTaskbar"=dword:00000001 
"NoSaveSettings"=dword:00000001 
"NoClose"=dword:00000001 
"NoNetHood"=dword:00000001 
"NoRun"=dword:00000001 
"NoDrives"=dword:00000000 
"NoTrayContextMenu"=dword:00000001 
"NoViewContextMenu"=dword:00000001 

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System] 

"DisableLockWorkstation"=dword:00000001
"DisableTaskMgr"=dword:00000001
"DisableChangePassword"=dword:00000001 

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Downloads

Download instructions:

Download demo registry source code - 1 Kb