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Q130942: PRB: WSAStartup() May Return WSAVERNOTSUPPORTED on Second Call

Article: Q130942
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.1
Operating System(s): 
Keyword(s): kbOSWin2000 kbGrpDSNet kbnetwork kbAPI kbOSWin310 kbOSWin95 kbWinsock kbSDKPlatform kbO
Last Modified: 21-OCT-2000

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The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) 3.1, used with:
   - Microsoft Windows 3.1 
- Microsoft Win32 Software Development Kit (SDK), used with:
   - the operating system: Microsoft Windows NT, versions 3.1, 3.5, 3.51, 4.0 
   - the operating system: Microsoft Windows 2000 
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SYMPTOMS
========

If two sections of code within the same process call WSAStartup(), the second
call to WSAStartup() fails and returns error WSAVERNOTSUPPORTED unless the
second call specifies the version negotiated in the first call.

This happens even if the requested version would normally be accepted. Often the
extra calls to WSAStartup() come from one or more DLLs loaded by the process.

RESOLUTION
==========

If multiple calls are made to WSAStartup(), the second call must request the
same version negotiated in the first call.

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

Some specific examples may help. Currently, if the version of Winsock requested
is 1.1 or greater, the negotiated version will be 1.1. If a version less than
1.1 is requested, the call fails and returns the WSAVERNOTSUPPORTED error.

Example One
-----------

First call : 1.1 requested
Second call: 1.1 requested
Result : Success

Example Two
-----------

First call : 2.0 requested
Second call: 1.1 requested
Result : Success

Example Three
-------------

First call : 2.0 requested
Second call: 2.0 requested
Result : WSAVERNOTSUPPORTED

Example Four
------------

First call : 1.1 requested
Second call: 2.0 requested
Result : WSAVERNOTSUPPORTED

Additional query words:

======================================================================
Keywords          : kbOSWin2000 kbGrpDSNet kbnetwork kbAPI kbOSWin310 kbOSWin95 kbWinsock kbSDKPlatform kbOSWinNT350 kbOSWinNT351 
Technology        : kbAudDeveloper kbSDKSearch kbWinSDKSearch
Version           : WINDOWS:3.1
Issue type        : kbprb

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