On a Windows Vista-based computer or on a Windows Server 2003-based computer, you try to access files on a Web Distributed Authoring and Versioning (WebDAV) site for the first time or you try to access Microsoft Office files on an http Web site. When you do this, you experience a long delay.
Additionally, you may experience the long delay during a later attempt to access a WebDAV share when the connection to the WebDAV workspace is closed.
Note If the connection to the workspace remains, you will not experience the long delay when you access the WebDAV share.
Multiple UNC provider (MUP) tries all the network providers sequentially according to the information that is specified in the registry. By default, the Server Message Block (SMB) redirector comes first. Therefore, MUP must try the SMB provider before MUP tries the Distributed Authoring and Versioning (DAV) provider.
If the router is configured to drop TCP packets that are directed to SMB ports (port 139 and port 445), MUP waits until the SMB connection times out. Then, MUP tries the DAV provider. This behavior causes the long time delay.
If you are using Windows Server 2003, see the "Workaround" section.
Update information for Windows Vista
To resolve this problem, install one of the following updates, as appropriate for your situation.
A hotfix is available to resolve this problem. All calls to WebDAV shares are converted from HTTP paths to UNC paths. These conversion routines set DavWWWRoot as the share name. After you apply the hotfix, MUP checks the share name before MUP tries any network provider. If the share name is DavWWWRoot, the call will not be forwarded to the SMB connections. This behavior avoids the delay that occurs when MUP tries the SMB provider.
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.
There are no prerequisites for installing this hotfix.
You must restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace a previously released hotfix.
To use one of the hotfixes in this package, you do not have to make any changes to the registry.
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.