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Article ID: 216091 - Last Review: January 10, 2015 - Revision: 4.0

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In Windows NT 4.0, it is possible to set up multiple hardware profiles using the Devices tool in Control Panel. The device for the network interface card (NIC) can be disabled on a per-profile basis.

In such a scenario, Sockets-based applications running on Windows NT 4.0 Service Pack 4 may fail unexpectedly. This problem has been observed in NetShow and Microsoft Exchange applications. The problem can also occur on multihomed computers where one of the NICs is disabled.


This problem occurs because the GetHostByName() API returns the old IP address owned previously by the disabled NIC.


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:
  • Windows Service Pack Center ( -or-

  • 152734  ( ) how to obtain the latest windows nt 4.0 service pack
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: (
This hotfix has been posted to the following Internet location as Rnr-fixi.exe (x86) and Rnr-fixa.exe (Alpha): (


Microsoft has confirmed that this is a problem in Windows NT 4.0 Service Pack 4. This problem was first corrected in Windows NT version 4.0 Service Pack 5.
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