Sign in with Microsoft
Sign in or create an account.
Hello,
Select a different account.
You have multiple accounts
Choose the account you want to sign in with.

Symptoms

Consider the following scenario:

  • You run an application or a service on a computer that is running Windows 7 or Windows Server 2008 R2.

  • The application or the service uses the Remote Desktop Connection ActiveX control (Mstscax.dll) to create multiple Remote Desktop Services sessions.

  • The application or the service creates multiple WinSock sessions in different Remote Desktop Services sessions.

In this scenario, the application or the service may crash randomly.

Cause

This issue occurs because of a race condition in Mstscax.dll. The race condition may occur when two threads try to register the same WinSock window class at the same time.

Resolution

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft website:

http://support.microsoft.com/contactus/?ws=supportNote The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply this hotfix, you must be running one of the following operating systems:

  • Windows 7

  • Windows 7 Service Pack 1 (SP1)

  • Windows Server 2008 R2

  • Windows Server 2008 R2 Service Pack 1 (SP1)

For more information about how to obtain a Windows 7 or Windows Server 2008 R2 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

976932 Information about Service Pack 1 for Windows 7 and for Windows Server 2008 R2

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

  • The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.

    Version

    Product

    SR_Level

    Service branch

    6.1.760
    0.
    16xxx

    Windows 7 and Windows Server 2008 R2

    RTM

    GDR

    6.1.760
    0.
    21xxx

    Windows 7 and Windows Server 2008 R2

    RTM

    LDR

    6.1.760
    1.
    17xxx

    Windows 7 and Windows Server 2008 R2

    SP1

    GDR

    6.1.760
    1.
    21xxx

    Windows 7 and Windows Server 2008 R2

    SP1

    LDR

  • The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2 and for Windows 7" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows 7

File name

File version

File size

Date

Time

Platform

Service branch

Wksprt.exe

6.1.7600.21097

223,744

24-Nov-2011

05:02

x86

X86_MICROSOFT-WINDOWS-T..ES-WORKSPACERUNTIME_31BF3856AD364E35_6.1.7600.21097_NONE_26BC3FF357B9E24F

Wksprt.exe

6.1.7601.21866

223,744

24-Nov-2011

04:55

x86

X86_MICROSOFT-WINDOWS-T..ES-WORKSPACERUNTIME_31BF3856AD364E35_6.1.7601.21866_NONE_28C2363754C8AAF6

Mstsc.exe

6.1.7600.21097

1,037,824

24-Nov-2011

06:20

x86

Not applicable

Mstsc.mof

Not applicable

1,199

22-Jul-2009

23:03

Not applicable

Not applicable

Mstsc.exe

6.1.7601.21866

1,051,648

24-Nov-2011

06:14

x86

Not applicable

Mstsc.mof

Not applicable

1,199

12-Nov-2010

23:41

Not applicable

Not applicable

Aaclient.dll

6.1.7600.21097

131,584

24-Nov-2011

06:20

x86

Not applicable

Aaclient.mof

Not applicable

1,261

22-Jul-2009

22:58

Not applicable

Not applicable

Mstscax.dll

6.1.7600.21097

2,706,432

24-Nov-2011

06:23

x86

Not applicable

Mstscax.mof

Not applicable

2,054

22-Jul-2009

23:02

Not applicable

Not applicable

Tsgqec.dll

6.1.7600.21097

36,864

24-Nov-2011

06:25

x86

Not applicable

Aaclient.dll

6.1.7601.17514

131,584

20-Nov-2010

12:18

x86

Not applicable

Aaclient.mof

Not applicable

1,261

10-Jun-2009

21:14

Not applicable

Not applicable

Mstscax.dll

6.1.7601.21866

3,217,920

24-Nov-2011

06:18

x86

Not applicable

Mstscax.mof

Not applicable

2,054

10-Jun-2009

21:17

Not applicable

Not applicable

Tsgqec.dll

6.1.7601.17514

36,864

20-Nov-2010

12:21

x86

Not applicable

For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

Service branch

Wksprt.exe

6.1.7600.21097

248,832

24-Nov-2011

05:33

x64

AMD64_MICROSOFT-WINDOWS-T..ES-WORKSPACERUNTIME_31BF3856AD364E35_6.1.7600.21097_NONE_82DADB7710175385

Wksprt.exe

6.1.7601.21866

249,344

24-Nov-2011

05:32

x64

AMD64_MICROSOFT-WINDOWS-T..ES-WORKSPACERUNTIME_31BF3856AD364E35_6.1.7601.21866_NONE_84E0D1BB0D261C2C

Mstsc.exe

6.1.7600.21097

1,101,312

24-Nov-2011

07:10

x64

Not applicable

Mstsc.mof

Not applicable

1,199

22-Jul-2009

23:22

Not applicable

Not applicable

Mstsc.exe

6.1.7601.21866

1,119,744

24-Nov-2011

07:05

x64

Not applicable

Mstsc.mof

Not applicable

1,199

12-Nov-2010

23:42

Not applicable

Not applicable

Aaclient.dll

6.1.7600.21097

158,720

24-Nov-2011

07:11

x64

Not applicable

Aaclient.mof

Not applicable

1,261

22-Jul-2009

23:18

Not applicable

Not applicable

Mstscax.dll

6.1.7600.21097

3,156,992

24-Nov-2011

07:15

x64

Not applicable

Mstscax.mof

Not applicable

2,054

22-Jul-2009

23:20

Not applicable

Not applicable

Tsgqec.dll

6.1.7600.21097

44,032

24-Nov-2011

07:19

x64

Not applicable

Aaclient.dll

6.1.7601.17514

158,720

20-Nov-2010

13:25

x64

Not applicable

Aaclient.mof

Not applicable

1,261

10-Jun-2009

20:31

Not applicable

Not applicable

Mstscax.dll

6.1.7601.21866

3,719,168

24-Nov-2011

07:09

x64

Not applicable

Mstscax.mof

Not applicable

2,054

10-Jun-2009

20:34

Not applicable

Not applicable

Tsgqec.dll

6.1.7601.17514

44,032

20-Nov-2010

13:27

x64

Not applicable

Mstsc.exe

6.1.7600.21097

1,037,824

24-Nov-2011

06:20

x86

Not applicable

Mstsc.mof

Not applicable

1,199

22-Jul-2009

23:03

Not applicable

Not applicable

Mstsc.exe

6.1.7601.21866

1,051,648

24-Nov-2011

06:14

x86

Not applicable

Mstsc.mof

Not applicable

1,199

12-Nov-2010

23:41

Not applicable

Not applicable

Aaclient.dll

6.1.7600.21097

131,584

24-Nov-2011

06:20

x86

Not applicable

Aaclient.mof

Not applicable

1,261

22-Jul-2009

22:58

Not applicable

Not applicable

Mstscax.dll

6.1.7600.21097

2,706,432

24-Nov-2011

06:23

x86

Not applicable

Mstscax.mof

Not applicable

2,054

22-Jul-2009

23:02

Not applicable

Not applicable

Tsgqec.dll

6.1.7600.21097

36,864

24-Nov-2011

06:25

x86

Not applicable

Aaclient.dll

6.1.7601.17514

131,584

20-Nov-2010

12:18

x86

Not applicable

Aaclient.mof

Not applicable

1,261

10-Jun-2009

21:14

Not applicable

Not applicable

Mstscax.dll

6.1.7601.21866

3,217,920

24-Nov-2011

06:18

x86

Not applicable

Mstscax.mof

Not applicable

2,054

10-Jun-2009

21:17

Not applicable

Not applicable

Tsgqec.dll

6.1.7601.17514

36,864

20-Nov-2010

12:21

x86

Not applicable

For all supported IA-64–based versions of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

Service branch

Wksprt.exe

6.1.7600.21097

457,216

24-Nov-2011

04:37

IA-64

IA64_MICROSOFT-WINDOWS-T..ES-WORKSPACERUNTIME_31BF3856AD364E35_6.1.7600.21097_NONE_26BDE3E957B7EB4B

Wksprt.exe

6.1.7601.21866

456,704

24-Nov-2011

04:28

IA-64

IA64_MICROSOFT-WINDOWS-T..ES-WORKSPACERUNTIME_31BF3856AD364E35_6.1.7601.21866_NONE_28C3DA2D54C6B3F2

Mstsc.exe

6.1.7600.21097

1,668,608

24-Nov-2011

05:42

IA-64

Not applicable

Mstsc.mof

Not applicable

1,199

22-Jul-2009

23:47

Not applicable

Not applicable

Mstsc.exe

6.1.7601.21866

1,703,424

24-Nov-2011

05:34

IA-64

Not applicable

Mstsc.mof

Not applicable

1,199

12-Nov-2010

23:42

Not applicable

Not applicable

Aaclient.dll

6.1.7600.21097

339,968

24-Nov-2011

05:43

IA-64

Not applicable

Aaclient.mof

Not applicable

1,261

22-Jul-2009

23:44

Not applicable

Not applicable

Mstscax.dll

6.1.7600.21097

6,094,336

24-Nov-2011

05:47

IA-64

Not applicable

Mstscax.mof

Not applicable

2,054

22-Jul-2009

23:46

Not applicable

Not applicable

Tsgqec.dll

6.1.7600.21097

97,792

24-Nov-2011

05:50

IA-64

Not applicable

Aaclient.dll

6.1.7601.21866

339,968

24-Nov-2011

05:34

IA-64

Not applicable

Aaclient.mof

Not applicable

1,261

10-Jun-2009

20:36

Not applicable

Not applicable

Mstscax.dll

6.1.7601.21866

6,309,376

24-Nov-2011

05:38

IA-64

Not applicable

Mstscax.mof

Not applicable

2,054

10-Jun-2009

20:38

Not applicable

Not applicable

Tsgqec.dll

6.1.7601.17514

97,792

20-Nov-2010

10:28

IA-64

Not applicable

Mstsc.exe

6.1.7600.21097

1,037,824

24-Nov-2011

06:20

x86

Not applicable

Mstsc.mof

Not applicable

1,199

22-Jul-2009

23:03

Not applicable

Not applicable

Mstsc.exe

6.1.7601.21866

1,051,648

24-Nov-2011

06:14

x86

Not applicable

Mstsc.mof

Not applicable

1,199

12-Nov-2010

23:41

Not applicable

Not applicable

Aaclient.dll

6.1.7600.21097

131,584

24-Nov-2011

06:20

x86

Not applicable

Aaclient.mof

Not applicable

1,261

22-Jul-2009

22:58

Not applicable

Not applicable

Mstscax.dll

6.1.7600.21097

2,706,432

24-Nov-2011

06:23

x86

Not applicable

Mstscax.mof

Not applicable

2,054

22-Jul-2009

23:02

Not applicable

Not applicable

Tsgqec.dll

6.1.7600.21097

36,864

24-Nov-2011

06:25

x86

Not applicable

Aaclient.dll

6.1.7601.17514

131,584

20-Nov-2010

12:18

x86

Not applicable

Aaclient.mof

Not applicable

1,261

10-Jun-2009

21:14

Not applicable

Not applicable

Mstscax.dll

6.1.7601.21866

3,217,920

24-Nov-2011

06:18

x86

Not applicable

Mstscax.mof

Not applicable

2,054

10-Jun-2009

21:17

Not applicable

Not applicable

Tsgqec.dll

6.1.7601.17514

36,864

20-Nov-2010

12:21

x86

Not applicable

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional file information

Additional file information for Windows 7 and for Windows Server 2008 R2

Additional files for all supported x86-based versions of Windows 7

File name

Update.mum

File version

Not applicable

File size

2,324

Date (UTC)

24-Nov-2011

Time (UTC)

16:39

Platform

Not applicable

File name

X86_95729a081c4ee4fb685e20eb6e11d6a9_31bf3856ad364e35_6.1.7601.21866_none_77711a200ac1cebe.manifest

File version

Not applicable

File size

1,458

Date (UTC)

24-Nov-2011

Time (UTC)

16:39

Platform

Not applicable

File name

X86_a8d584d4e7a23313684e5e0e8455f260_31bf3856ad364e35_6.1.7600.21097_none_4fb0d622916588d1.manifest

File version

Not applicable

File size

1,458

Date (UTC)

24-Nov-2011

Time (UTC)

16:39

Platform

Not applicable

File name

X86_microsoft-windows-t..es-workspaceruntime_31bf3856ad364e35_6.1.7600.21097_none_26bc3ff357b9e24f.manifest

File version

Not applicable

File size

8,960

Date (UTC)

24-Nov-2011

Time (UTC)

07:16

Platform

Not applicable

File name

X86_microsoft-windows-t..es-workspaceruntime_31bf3856ad364e35_6.1.7601.21866_none_28c2363754c8aaf6.manifest

File version

Not applicable

File size

8,960

Date (UTC)

24-Nov-2011

Time (UTC)

07:14

Platform

Not applicable

File name

X86_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.21097_none_4e3352cb9b8f38dd.manifest

File version

Not applicable

File size

21,618

Date (UTC)

24-Nov-2011

Time (UTC)

07:26

Platform

Not applicable

File name

X86_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21866_none_5039490f989e0184.manifest

File version

Not applicable

File size

21,618

Date (UTC)

24-Nov-2011

Time (UTC)

07:18

Platform

Not applicable

File name

X86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.21097_none_30450cf3401fdf5c.manifest

File version

Not applicable

File size

131,498

Date (UTC)

24-Nov-2011

Time (UTC)

07:27

Platform

Not applicable

File name

X86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21866_none_324b03373d2ea803.manifest

File version

Not applicable

File size

140,967

Date (UTC)

24-Nov-2011

Time (UTC)

17:12

Platform

Not applicable

Additional files for all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

Amd64_4bbcb10d4b83f5e4aa88ef1e1875feca_31bf3856ad364e35_6.1.7601.21866_none_0b203665052f7f15.manifest

File version

Not applicable

File size

2,205

Date (UTC)

24-Nov-2011

Time (UTC)

16:39

Platform

Not applicable

File name

Amd64_647ed0db8315f15ac6efeb075ea0a7b9_31bf3856ad364e35_6.1.7600.21097_none_87b2bdb85b8f48ec.manifest

File version

Not applicable

File size

2,205

Date (UTC)

24-Nov-2011

Time (UTC)

16:39

Platform

Not applicable

File name

Amd64_microsoft-windows-t..es-workspaceruntime_31bf3856ad364e35_6.1.7600.21097_none_82dadb7710175385.manifest

File version

Not applicable

File size

10,551

Date (UTC)

24-Nov-2011

Time (UTC)

08:10

Platform

Not applicable

File name

Amd64_microsoft-windows-t..es-workspaceruntime_31bf3856ad364e35_6.1.7601.21866_none_84e0d1bb0d261c2c.manifest

File version

Not applicable

File size

10,551

Date (UTC)

24-Nov-2011

Time (UTC)

08:03

Platform

Not applicable

File name

Amd64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.21097_none_aa51ee4f53ecaa13.manifest

File version

Not applicable

File size

21,624

Date (UTC)

24-Nov-2011

Time (UTC)

08:15

Platform

Not applicable

File name

Amd64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21866_none_ac57e49350fb72ba.manifest

File version

Not applicable

File size

21,624

Date (UTC)

24-Nov-2011

Time (UTC)

08:07

Platform

Not applicable

File name

Amd64_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.21097_none_8c63a876f87d5092.manifest

File version

Not applicable

File size

131,504

Date (UTC)

24-Nov-2011

Time (UTC)

08:16

Platform

Not applicable

File name

Amd64_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21866_none_8e699ebaf58c1939.manifest

File version

Not applicable

File size

140,973

Date (UTC)

24-Nov-2011

Time (UTC)

17:56

Platform

Not applicable

File name

Update.mum

File version

Not applicable

File size

2,340

Date (UTC)

24-Nov-2011

Time (UTC)

16:39

Platform

Not applicable

File name

Wow64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.21097_none_b4a698a1884d6c0e.manifest

File version

Not applicable

File size

13,023

Date (UTC)

24-Nov-2011

Time (UTC)

06:57

Platform

Not applicable

File name

Wow64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21866_none_b6ac8ee5855c34b5.manifest

File version

Not applicable

File size

13,023

Date (UTC)

24-Nov-2011

Time (UTC)

06:53

Platform

Not applicable

File name

X86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.21097_none_30450cf3401fdf5c.manifest

File version

Not applicable

File size

131,498

Date (UTC)

24-Nov-2011

Time (UTC)

07:27

Platform

Not applicable

File name

X86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21866_none_324b03373d2ea803.manifest

File version

Not applicable

File size

140,967

Date (UTC)

24-Nov-2011

Time (UTC)

17:56

Platform

Not applicable

Additional files for all supported IA-64–based versions of Windows Server 2008 R2

File name

Ia64_5bf73fc8995809913658d382497bd8d3_31bf3856ad364e35_6.1.7601.21866_none_3d78d9d3a19d1ae3.manifest

File version

Not applicable

File size

2,201

Date (UTC)

24-Nov-2011

Time (UTC)

16:38

Platform

Not applicable

File name

Ia64_60a4ff337236f628810618f0876a3551_31bf3856ad364e35_6.1.7600.21097_none_4319c4833c97475f.manifest

File version

Not applicable

File size

2,201

Date (UTC)

24-Nov-2011

Time (UTC)

16:38

Platform

Not applicable

File name

Ia64_microsoft-windows-t..es-workspaceruntime_31bf3856ad364e35_6.1.7600.21097_none_26bde3e957b7eb4b.manifest

File version

Not applicable

File size

10,549

Date (UTC)

24-Nov-2011

Time (UTC)

07:43

Platform

Not applicable

File name

Ia64_microsoft-windows-t..es-workspaceruntime_31bf3856ad364e35_6.1.7601.21866_none_28c3da2d54c6b3f2.manifest

File version

Not applicable

File size

10,549

Date (UTC)

24-Nov-2011

Time (UTC)

07:35

Platform

Not applicable

File name

Ia64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.21097_none_4e34f6c19b8d41d9.manifest

File version

Not applicable

File size

21,621

Date (UTC)

24-Nov-2011

Time (UTC)

07:44

Platform

Not applicable

File name

Ia64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21866_none_503aed05989c0a80.manifest

File version

Not applicable

File size

21,621

Date (UTC)

24-Nov-2011

Time (UTC)

07:37

Platform

Not applicable

File name

Ia64_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.21097_none_3046b0e9401de858.manifest

File version

Not applicable

File size

131,501

Date (UTC)

24-Nov-2011

Time (UTC)

07:45

Platform

Not applicable

File name

Ia64_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21866_none_324ca72d3d2cb0ff.manifest

File version

Not applicable

File size

140,970

Date (UTC)

24-Nov-2011

Time (UTC)

16:39

Platform

Not applicable

File name

Update.mum

File version

Not applicable

File size

1,947

Date (UTC)

24-Nov-2011

Time (UTC)

16:38

Platform

Not applicable

File name

Wow64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.21097_none_b4a698a1884d6c0e.manifest

File version

Not applicable

File size

13,023

Date (UTC)

24-Nov-2011

Time (UTC)

06:57

Platform

Not applicable

File name

Wow64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21866_none_b6ac8ee5855c34b5.manifest

File version

Not applicable

File size

13,023

Date (UTC)

24-Nov-2011

Time (UTC)

06:53

Platform

Not applicable

File name

X86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.21097_none_30450cf3401fdf5c.manifest

File version

Not applicable

File size

131,498

Date (UTC)

24-Nov-2011

Time (UTC)

07:27

Platform

Not applicable

File name

X86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21866_none_324b03373d2ea803.manifest

File version

Not applicable

File size

140,967

Date (UTC)

24-Nov-2011

Time (UTC)

16:39

Platform

Not applicable

Need more help?

Want more options?

Explore subscription benefits, browse training courses, learn how to secure your device, and more.

Communities help you ask and answer questions, give feedback, and hear from experts with rich knowledge.

Was this information helpful?

What affected your experience?
By pressing submit, your feedback will be used to improve Microsoft products and services. Your IT admin will be able to collect this data. Privacy Statement.

Thank you for your feedback!

×