Microsoft KB Archive/164933

= How to allow Poolmon.exe to run by setting GlobalFlag value =

Article ID: 164933

Article Last Modified on 11/1/2006

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APPLIES TO


 * Microsoft Windows NT Workstation 3.5
 * Microsoft Windows NT Workstation 3.51
 * Microsoft Windows NT Workstation 4.0 Developer Edition
 * Microsoft Windows NT Server 3.5
 * Microsoft Windows NT Server 3.51
 * Microsoft Windows NT Server 4.0 Standard Edition

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This article was previously published under Q164933



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:

256986 Description of the Microsoft Windows Registry



SYMPTOMS
The utility Poolmon.exe located on the Windows NT CD-ROM can be used to track memory usage in both paged and nonpaged pools of memory. When POOLMON is run from the command prompt of Windows NT, the following error is displayed:

Query pooltags Failed c0000002



CAUSE
Poolmon.exe uses a global pooltag in the registry located at a value called GlobalFlag. The default value for GlobalFlag is 0, so Windows NT does not expend extra overhead in gathering pooltag information.



RESOLUTION
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.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

To allow Windows NT to gather pooltag information, the GlobalFlag value must be changed using Registry Editor (Regedt32.exe). Before making changes, write down the current value of GlobalFlag so that it can be reset once running Poolmon.exe is no longer necessary.

The following hex values for GlobalFlag will set up memory tagging in Windows NT for the following versions:

Windows NT 3.5: 0x01000000

Windows NT 3.51: 0x00000400

Windows NT 4.0: 0x00000400

If you are running Windows NT version 3.51 or 4.0 but do not have the Windows NT 4.0 Resource Kit, follow these steps.

To change the value of the GlobalFlag, you need to modify its value in the registry.  Start Registry Editor (Regedt32.exe) and locate the following subkey:

 Double-click on the GlobalFlag Value on the right pane. In the Data Type field, select REG_DWORD and click OK.  In the Data Field, type in either 01000000 or 00000400, depending on the version of Windows NT. Select the Hex option and click OK.

     Range:   0 - 0xFFFFFFFF (not continuous) Default: 0  Quit Registry Editor, shutdown, and restart your computer.</li></ol>

If you have a computer running Windows NT 4.0 and you have the resource kit, there is utility called GFLAGS. GFLAGS is a GUI tool that enables a developer or system administrator to edit the NtGlobalFlag settings for Windows NT Server or Windows NT Workstation without having to make manual changes in the registry.

To use this utility to enable Pool tagging:
 * 1) Double-click on the Gflags.exe file in the resource kit directory or open a MS-DOS command prompt and type in GFLAGS and press Enter.
 * 2) After the GFLAGS window opens, set the destination in the upper windows to System Registry.
 * 3) In the lower portion of the window, click to select the "Enable Pool Tagging" check box.
 * 4) The computer running Windows NT will have to be restarted for the change to take affect.

GFLAGS can also set the flag required for the kernel feature of Oh.exe, a tool that shows the handles of open windows. For usage information, at a MS- DOS command prompt type:

gflags /?

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MORE INFORMATION
GlobalFlag consists of 32 bits that are used as switches to enable or disable several different advanced internal system diagnostics and troubleshooting tests.

Note In Windows NT versions 3.51 and earlier, changing the value of this entry to 0x20100000 disabled the OS/2 subsystem and caused OS/2-bound applications to run in a virtual DOS computer. This does not work in Windows NT 4.0.

Keywords: kbprb kbusage KB164933

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