DOCUMENT:Q103475  04-NOV-1993  [W_NT]
TITLE   :Starting Applications with /REALTIME May Hang Windows NT
PRODUCT :Windows NT
PROD/VER:3.10
OPER/SYS:WINDOWS
KEYWORDS:buglist3.10

----------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Windows NT operating system version 3.1
 - Microsoft Windows NT Advanced Server version 3.1
----------------------------------------------------------------------


SYMPTOMS
========

From a Command Prompt (CMD.EXE), if you start an application with
the /REALTIME switch, Windows NT may appear to hang.

CAUSE
=====

The /REALTIME switch starts an application at a higher priority level
than normal. This gives the application more processor time to use
during its execution. If you use this switch on applications that are
not designed for it, Windows NT will not respond to any other commands
and will appear to hang, even though Windows NT is actually still
running and executing as instructed by the command line switch.

RESOLUTION
==========

To prevent this situation from occurring, it is possible for the
Administrator of the system to set a User's rights so they are unable
to use this feature of setting thread priorities. Power Users are
given the right to Increase Scheduling Priorities by default.

To remove the right to Increase Scheduling Priorities, use the
following procedure:

1. Open the User Manager in the Administrative Tools group.

2. Select Policy from the menu and then select User Rights.

3. Select the Show Advanced User Rights check box.

4. Open the Rights box.

5. Select Increase Scheduling Priority.

6. Remove any desired Users or Groups from the Grant To box.

Without the Increase Scheduling Priority right, users will be unable
to use the /REALTIME switch.

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

Steps to Reproduce Problem
--------------------------

1. Open a Command Prompt from the Main group.

2. Type the following command:

   START /REALTIME EDIT.COM

3. When Edit is opened, select the File menu.

At this point, the system will not respond to any keyboard or mouse
commands.

Additional reference words: 3.10 W_NTAS hung lock freeze
KBCategory:
KBSubcategory: ntap

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1993.