16-bit Windows-Based Programs Support Up to 26 DDE Connections

This article was previously published under Q198573
This article has been archived. It is offered "as is" and will no longer be updated.
A 16-bit Windows-based application, which uses many DDE connections, failsafter a while when running on Windows NT. The application works correctlyon Windows 3.1.
After more than 26 concurrent DDE connections have been created, an error0x400f (a system API failed inside of the DDEML) is returned when closingthe twenty-seventh connection. This problem is due to a timer, which isassociated with a window, not being freed when the relevant window isdestroyed.
To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to:
For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:
Microsoft has confirmed this to be a problem in Windows NT version 4.0. This problem was first corrected in Windows NT version 4.0 Service Pack 5.
Exchange Dynamic Data 4.00 WOW DMLERR_SYS_ERROR

Article ID: 198573 - Last Review: 11/02/2013 21:59:00 - Revision: 3.0

Microsoft Windows NT Workstation 4.0 Developer Edition, Microsoft Windows NT Server 4.0 Standard Edition, Microsoft Windows NT Server 4.0 Enterprise Edition

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