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Q150420: Err: Win16 Subsystem Unable to Enter Protected Mode

Article: Q150420
Product(s): Microsoft Windows NT
Version(s): 3.5,3.51
Operating System(s): 
Keyword(s): 
Last Modified: 20-FEB-2002

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The information in this article applies to:

- Microsoft Windows NT Workstation versions 3.5, 3.51 
- Microsoft Windows NT Server versions 3.5, 3.51 
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SYMPTOMS
========

When you attempt to access a 16-bit application from Windows NT and are using
Fprot.exe, the following error message is displayed:

  The Win16 Subsystem was unable to enter Protected Mode, DOSX.EXE must be in
  your AUTOEXEC.NT and present in your PATH.

CAUSE
=====

Fprot.exe inadvertently changes the file's attributes to read/hidden/system
attributes. The following may be affected:

- WINNTxx

- WINNTxx\SYSTEM

- WINNTxx\SYSTEM32

- WINNTxx\SYSTEM32\DRIVERS

- WINNTxx\SYSTEM32\REPAIR

RESOLUTION
==========

Compare the damaged system with a fresh install of NT on a second computer and
reset the attributes with either the "attrib" command or File Manager.


MORE INFORMATION
================

ATTRIB [+R | -R] [+A | -A ] [+S | -S] [+H | -H] [[drive:] [path] filename]
[/S]

+   Sets an attribute.
-   Clears an attribute.
R   Read-only file attribute.
A   Archive file attribute.
S   System file attribute.
H   Hidden file attribute.
/S  Processes files in all directories in the specified path.

Additional query words:

======================================================================
Keywords          :  
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNT351search kbWinNT350search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search
Version           : :3.5,3.51

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