Microsoft KB Archive/326591

= Maximum NT User Handles Per Process Is 10,000 in Windows 2000 =

Article ID: 326591

Article Last Modified on 2/22/2007

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APPLIES TO


 * Microsoft Windows 2000 Server
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Professional Edition

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This article was previously published under Q326591



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
Programs that require many NT User handles may stop working when they reach approximately 10,000 handles. For example, this might occur when a program tries to use many NetDDE links.



CAUSE
There is a hard-coded limit of 10,000 NT User handles. This is designed to prevent &quot;bad&quot; (incorrectly behaving) programs from allocating too many NT User handles.



Service Pack Information
To resolve this problem, obtain the latest service pack for Microsoft Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

Hotfix Information
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows 2000 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.   Date         Time   Version        Size       File name --  15-Aug-2002  14:13  5.0.2195.5265     42,256  Basesrv.dll 15-Aug-2002 14:13  5.0.2195.5907    222,992  Gdi32.dll 15-Aug-2002 14:13  5.0.2195.6011    708,880  Kernel32.dll 15-Aug-2002 14:13  5.0.2195.4733    332,560  Msgina.dll 15-Aug-2002 14:13  5.0.2195.6000    379,664  User32.dll 15-Aug-2002 14:13  5.0.2195.5968    369,936  Userenv.dll 15-Aug-2002 14:10  5.0.2195.6017  1,642,416  Win32k.sys 15-Aug-2002 08:30  5.0.2195.6013    179,472  Winlogon.exe 15-Aug-2002 14:13  5.0.2195.5935    243,472  Winsrv.dll 15-Aug-2002 14:13  5.0.2195.6011    708,880  Kernel32.dll 15-Aug-2002 14:13  5.0.2195.6017  1,642,416  Win32k.sys 15-Aug-2002 14:13  5.0.2195.5935    243,472  Winsrv.dll

Required Registry Values
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.

To use this hotfix, you must create or modify the following registry values to specify the number of NT User handles that you want to allow. The maximum number is 18,000.

HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows\USERProcessHandleQuota

HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows\USERPostMessageLimit (REG_DWORD)



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Microsoft Windows 2000 Service Pack 4.



MORE INFORMATION
For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base:

265173 The Datacenter Program and Windows 2000 Datacenter Server Product

For additional information about how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base:

296861 Use QChain.exe to Install Multiple Hotfixes with One Reboot

Keywords: kbhotfixserver kbqfe kbshell kbwin2ksp4fix kbbug kbfix kbwin2000presp4fix KB326591

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