DOCUMENT:Q255890  08-AUG-2001  [winnt]
TITLE   :PRB: DCOM Client Hangs When You Pass Callback Interface Pointer
PRODUCT :Microsoft Windows NT
PROD/VER::4.0; winnt:4.0
OPER/SYS:
KEYWORDS:kbDCOM kbGrpDSCom kbDSupport

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The information in this article applies to:

 - Microsoft Windows NT Advanced Server, version 4.0 
 - Microsoft Windows NT Server version 4.0 
 - Microsoft Windows NT Server version 4.0, Terminal Server Edition 
 - Microsoft Windows NT Server, Enterprise Edition version 4.0 
 - Microsoft Windows NT Workstation version 4.0 
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SYMPTOMS
========

When a Distributed Component Object Model (DCOM) client makes a remote method
call to pass a callback interface pointer to the server, and the SYSTEM account
does not have access permissions on the client computer, a problem may occur. If
the User Datagram Protocol (UDP) is used, the client may stop responding (hang).
If the Transmission Control Protocol/Internet Protocol (TCP/IP) is used, the
application may return the E_OUTOFMEMORY error.

CAUSE
=====

By default, the SYSTEM account does not have access permissions on the client
computer; as a result, DCOM cannot marshall the callback interface pointer.

RESOLUTION
==========

To resolve this problem, give access permissions to the SYSTEM account. For DCOM
to work, you must assign access permissions to the SYSTEM account.

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

To check the default access permissions, perform the following steps:

1. Start Dcomcnfg.exe.

2. Click the Default Security tab, and then click Edit Default for default
   access permissions. The list must include SYSTEM: allow access. If the list
   is empty, then the launching user and the SYSTEM account have access
   permissions.

REFERENCES
==========

For more information on COM security, see the following MSDN Online Library help
topic:

   http://msdn.microsoft.com/library/psdk/com/security_0icz.htm

Additional query words: SYSTEM hang

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Keywords          : kbDCOM kbGrpDSCom kbDSupport 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400search kbWinNTS400 kbWinNTAdvSerSearch kbWinNTAdvServ400 kbNTTermServ400 kbNTTermServSearch
Version           : :4.0; winnt:4.0
Issue type        : kbprb

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