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Q235496: Enabling a Memory.dmp File Capture Using the GUI or the Registry

Article: Q235496
Product(s): Microsoft Windows NT
Version(s): winnt:3.5,3.51,4.0
Operating System(s): 
Keyword(s): kbenv
Last Modified: 11-JUN-2002

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The information in this article applies to:

- Microsoft Windows NT Server versions 3.5, 3.51, 4.0 
- Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 
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IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

  Q256986 Description of the Microsoft Windows Registry

SUMMARY
=======

This article describes how to enable a Memory.dmp file capture using the
graphical user interface (GUI) of Windows NT or by making changes to the
registry.

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

To enable Windows NT to capture a Memory.dmp file, you must be able to gain
access to the GUI or the registry file. Use the appropriate method to enable
Windows NT to capture a Memory.dmp file.

Method 1: Enabling a Memory.dmp File Capture Using the GUI
----------------------------------------------------------

1. Click Start, point to Settings, click Control Panel, and then double-click
  System.

2. On the Startup/Shutdown tab in the Recovery section, you can choose from the
  following options:

   - Write an event to the system log
     This option is enabled by default in Windows NT Server 4.0 Service Pack 4
     or later. If the computer stops responding, an event is written to the
     system log, which you can view using Event Viewer. For example:

  Event ID: 1001
  Source: Save Dump
  Description: The computer has rebooted from a bugcheck. The bugcheck was:
  0xc000021a (0xe1270188, 0x00000001, 0x00000000, 0x00000000). Microsoft
  Windows NT (v15.1381). A dump was saved in: C:\Winnt\Memory.dmp.

   - Send an administrative alert
     This option performs a net send command and sends an alert over the network
     to the administrator.

   - Write debugging information to
     This option enables the capture of a dump file. It also specifies the
     location to store the dump file (the default location is the
     %SystemRoot%\Memory.dmp folder).

     NOTE: Although you can redirect the Memory.dmp file to another drive or
     partition, you must have sufficient space on the partition. When a save
     dump operation is performed, the contents of kernel mode address space are
     temporarily stored in the page file on the system partition and are then
     moved to the alternate location when the computer is restarted. For
     Windows NT to write a memory dump, the paging file on the system drive
     must be large enough to hold all of physical RAM plus 1 megabyte (MB).

   - Overwrite an existing file
     If you choose this option, a new Memory.dmp file overwrites a previous
     Memory.dmp file (which conserves disk space).

   - Automatically reboot
     If you choose this option, the computer is restarted after a bugcheck
     occurs.

Method 2: Enabling a Memory.dmp File Capture Using the Registry
---------------------------------------------------------------

WARNING: If you use Registry Editor incorrectly, you may cause serious problems
that may require you to reinstall your operating system. Microsoft cannot
guarantee that you can solve problems that result from using Registry Editor
incorrectly. Use Registry Editor at your own risk.

You may encounter situations when you cannot gain access to the GUI of Windows
NT. Use the appropriate method to capture a Memory.dmp file using the registry.

For Computers Using the FAT File System:

1. Boot from an MS-DOS disk.

2. Locate the %SystemRoot%\System32\Config folder (%SystemRoot% is the name of
  the folder in which you installed Windows NT).

3. Locate the System file (without any extension) and copy it to a disk.

4. Insert the disk into the drive of another Windows NT-based computer, and then
  start Registry Editor (Regedt32.exe).

5. Ensure the HKEY_LOCAL_MACHINE hive is selected.

6. On the Registry menu, click Load Hive.

7. Locate the System file, and then click Open.

8. The Load Hive dialog box appears. In the Key Name box, type a temporary name
  (for example, "test" (without the quotation marks)), and then click OK.

9. A key named Test appears. This is a copy of your System hive from the other
  Windows NT-based computer.

10. Locate the following registry key:

  HKEY_LOCAL_MACHINE\TEST\ControlSet001\Control\Crash Control

11. On the right-hand side of the screen, the following values that correspond
  to the GUI interface are displayed:

  Value Name: AutoReboot
  Data Type: REG_DWORD
  Data: 0|1 (Disabled|Enabled)

  Value Name: CrashDumpEnabled
  Data Type: REG_DWORD
  Data: 0|1 (Disabled|Enabled)

  Value Name: DumpFile
  Data Type: REG_EXPAND_SZ
  Data: %SystemRoot%\Memory.dmp (location to save the dump file)

  Value Name: LogEvent
  Data Type: REG_DWORD
  Data: 0|1 (Disabled|Enabled) Logs an event to the System log when a crash
  occurs

  Value Name: Overwrite
  Data Type: REG_DWORD
  Data: 0|1 (Disabled|Enabled) Overwrites an existing dump file

  Value Name: SendAlert
  Data Type: REG_DWORD
  Data: (Disabled|Enabled) Sends an administrative alert

12. After you make the appropriate changes, copy the updated System file back to
  the %SystemRoot%\System32\Config folder on the original computer.

For Computers Using the NTFS File System:

Because of the security features in the file system, you cannot simply copy the
file, make changes, and then copy the file back to the computer. To gain access
to the file system, you must perform a parallel installation of Windows NT. A
parallel installation puts another copy of the operating system in another
folder, which allows you to gain access to the file system. After the parallel
installation is finished, use the following steps:

1. Start Registry Editor (Regedt32.exe).

2. Ensure the HKEY_LOCAL_MACHINE hive is selected.

3. On the Registry menu, click Load Hive.

4. Locate the %SystemRoot%\System32\Config folder on the original installation
  of Windows NT, click the System file, and then click Open.

5. The Load Hive dialog box appears. In the Key Name box, type an appropriate
  temporary name (for example, "test" (without the quotation marks)). A key
  named Test appears. This is the System hive from the other installation of
  Windows NT.

6. Locate the following registry key:

  HKEY_LOCAL_MACHINE\TEST\ControlSet001\Control\Crash Control

7. On the right-hand side of the page, the values that correspond to the GUI
  interface are displayed. Make and save the appropriate changes.

8. Restart your original installation of Windows NT.

For Remote Computers:

1. Start Registry Editor (Regedt32.exe).

2. On the Registry menu, click Select Computer, and then type the name of the
  remote computer.

3. Locate the following registry key:

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CrashControl

4. On the right-hand side of the page, the values that correspond to the GUI
  interface are displayed. Make and save the appropriate changes.

5. Quit Registry Editor, and then restart the computer.

REFERENCES
==========

For additional information, please click the article numbers below to view the
articles in the Microsoft Knowledge Base:

Q130536 Windows NT Does Not Save Memory Dump File After a Crash

Q141468 Additional Pagefile Created Setting Up Memory Dump

Q174630 Windows NT Restarts Continuously with Blue Screen

Q244139 Windows 2000 Feature Allows a Memory.dmp File to Be Generated
[ntrelease]

Additional query words:

======================================================================
Keywords          : kbenv 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search
Version           : winnt:3.5,3.51,4.0
Issue type        : kbinfo

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

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