Duplicated Files in Windows NT System Subdirectories

• Microsoft Windows NT operating system, version 3.1
• Microsoft Windows NT Advanced Server, version 3.1

Windows NT Setup installs a small group of files in more than one location. The files are present in both the System Root (%systemroot%) directory and in the %systemroot%\SYSTEM32 directory, or in both the %systemroot%\SYSTEM32 and %systemroot%\SYSTEM directories. Some examples of these files include TASKMAN.EXE, VER.DLL, and WRITE.EXE.

The Windows NT system executable files must be in the SYSTEM32 directory for security reasons. The SYSTEM32 directory is first on the search path; if someone placed a dangerous version of a system file (such as a buggy copy of WRITE.EXE, for example) into another directory on the path, the version shipped with the system runs instead. Some programs must be in the System Root or in the SYSTEM directory for compatibility with 16-bit Windows 3.1. For example, some application setup programs create a program item and set its command line to "%systemroot%\WRITE.EXE README.WRI". In this case, WRITE.EXE must be in the System Root directory. A more obscure example occurs when the Setup program for an application does not run unless it can find TASKMAN.EXE in the System Root directory. This Setup program should call GetWindowsDirectory() to find TASKMAN.EXE; why it does not is not known.

The duplicate files are as follows:

%systemroot% and %systemroot%\SYSTEM32

   NOTEPAD.EXE
   TASKMAN.EXE
   WRITE.EXE

%systemroot%\SYSTEM and %systemroot%\SYSTEM32

   COMMDLG.DLL
   MMSYSTEM.DLL
   MMTASK.TSK
   OLECLI.DLL
   OLESVR.DLL
   SETUP.INF (identical name, different content)
   SHELL.DLL
   VER.DLL