You cannot open a mapped offline-files drive during CSC synchronization in Windows XP (840749)

SYMPTOMS

When you try to open a mapped offline-files drive by using Windows Explorer during client side caching (CSC) synchronization of offline files, you may receive the following error message:

My Computer
Drive_letter:\ refers to a location that is unavailable. It could be on a hard drive on this computer, or on a network. Check to make sure that the disk is properly inserted, or that you are connected to the Internet or your network, and then try again. If it still cannot be located, the information might have been moved to a different location.

You cannot remove the mapped drive, and if you try to disconnect the network connection that the mapped drive uses to connect to the network share, you receive the following error message:

The network connection could not be found.

CAUSE

The offline-files synchronization process temporarily maps an additional auxiliary drive letter at the time of synchronization, and this process typically determines that the letter E is the next available drive letter. If you start Windows Explorer during the synchronization process, it enumerates all drives, including the auxiliary offline-files drive. This mapped offline-files drive becomes orphaned after the CSC synchronization process is completed because the Windows Explorer window is not informed of the auxiliary device removal after synchronization.

RESOLUTION

Service pack information

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

322389 How to obtain the latest Windows XP service pack

Hotfix information

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft Windows XP service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this hotfix has the file attributes (or later) 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 tool in Control Panel.

Windows XP

   Date         Time   Version            Size    File name
   -----------------------------------------------------------
   19-Apr-2004  22:59  5.1.2600.1517      40,448  Ntlanman.dll

Windows XP 64-Bit Edition

   Date         Time   Version            Size    File name     Platform
   ---------------------------------------------------------------------
   19-Apr-2004  22:56  5.1.2600.1517     115,712  Ntlanman.dll  IA-64
   19-Apr-2004  22:59  5.1.2600.1517      40,448  Wntlanman.dll x86