A computer that is running Terminal Services stops responding and you receive an error message in Windows 2000 or in Windows XP: "Stop Error 0x7F"

A computer that is running Terminal Services may stop responding. When this problem occurs, you receive the following Stop error message: The Stop error occurs in the Win32k.sys file.

When you shut down and restart the computer, the computer starts as usual. However, the Stop error recurs regularly.

This problem may occur if the computer is running Windows XP or Microsoft Windows 2000.

This problem occurs because a program may create up to 100 nested windows. During cleanup, there may not be sufficient stack space for the current thread to handle all the functions that are needed to clean up all the window objects.

After you apply this hotfix, a program can create up to 50 nested windows. If a program tries to create more than 50 nested windows, the program fails.

Windows XP

Service pack information

To resolve this problem, obtain the latest service pack for Windows XP. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. 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 Web site: Note 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 have Windows XP Service Pack 1 installed on the computer.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows 2000

Service pack information

To resolve this problem, obtain the latest service pack for Windows 2000. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. 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 Web site: Note 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 have Windows 200 Service Pack 3 installed on the computer.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Microsoft Windows 2000 Service Pack 4.

For more information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the following article number to view the article in the Microsoft Knowledge Base:

Windows XP registry information

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

After you apply this hotfix, you can use the NestedWindowLimit registry entry to set the maximum number of nested windows. You can set the maximum to any value between 50 and 100.

Warning If you set a value other than 50, Windows might stop responding, and you might receive a "Stop Error 0x7F" error message. If this problem occurs, restore the value to 50. Or, remove the registry entry.

To set the maximum number of nested windows, follow these steps:

1. Click Start, type regedit in the Start Search box, and then press ENTER.
2. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type USERNestedWindowLimit , and then press ENTER.
5. Right-click USERNestedWindowLimit, and then click Modify.
6. Under Base, click Decimal.
7. In the Value data box, type a new value.
8. Click OK, and then exit Registry Editor.