A significant delay occurs when you try to expand a subfolder of a network drive in Windows Explorer on a Windows Vista-based or Windows Server-based client computer

On a Windows Vista-based client computer or on a Windows Server-based client computer, you map a network drive to a shared folder on a wide area network (WAN).The shared folder contains many subfolders. Then, you view the network drive in Windows Explorer. When you expand one of the subfolders in the left pane (folder tree), you may experience a very long delay while Windows Explorer enumerates the content of the subfolder.

Notes

• This long delay occurs even if the enumerated folder has only a few subfolders or files.
• This issue does not occur if you access the subfolder through the right pane of Windows Explorer.
• This issue does not occur in Windows XP or in Windows Server 2003.

This problem occurs because, when Windows Explorer expands a folder in the folder tree, it starts a background enumeration on all child-items of that tree. When Windows Explorer performs the enumeration over a WAN, and there are many folders, there is a significant delay between the user clicking and the folder expanding.

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 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 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.

Important Windows Vista and Windows Server 2008 hotfixes are included in the same packages. However, only one of these products may be listed on the ��Hotfix Request�� page. To request the hotfix package that applies to both Windows Vista and Windows Server 2008, just select the product that is listed on the page.

Prerequisites

To apply this hotfix, the computer must run one of the following:

• Windows Vista SP1
• Windows Server 2008

Restart requirement

You have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other previously released hotfixes.

Registry information

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

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 Vista and Windows Server 2008 file information notes

The MANIFEST files (.manifest) and MUM files (.mum) installed for each environment are listed separately. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files (attributes not listed) are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows Server 2008 and Windows Vista
For all supported x64-based versions of Windows Server 2008 and Windows Vista
For all supported Itanium-based versions of Windows Server 2008 and Windows Vista

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

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

Additional file information for Windows Server 2008 and Windows Vista

Additional files for all supported x86-based versions of Windows Server 2008 and Windows Vista

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

Additional files for all supported Itanium-based versions of Windows Server 2008