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Q138014: File May Be Truncated to Zero Bytes When Copied Onto Itself

Article: Q138014
Product(s): Microsoft Windows 95.x Retail Product
Version(s): 
Operating System(s): 
Keyword(s): kbfile kbnetwork msnets win95
Last Modified: 15-JUN-2001

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The information in this article applies to:

- Microsoft Windows 95 
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SYMPTOMS
========

When you try to copy a file onto itself, you receive a Confirm File Replace
dialog box prompting you to confirm that you want to replace the existing file.
If you click Yes, the file may be truncated to zero bytes. If you click No, the
file is unchanged.

This problem occurs only when you copy a file onto itself using two different
views of the same network resource (such as when you have two different drive
letters mapped to the same network resource, or when you have two UNC
connections to the same network resource), or when you copy a file onto itself
using a drive created with the SUBST command.

NOTE: If you try to move (rather than copy) a file in this manner, the file may
be deleted.

RESOLUTION
==========

This issue is resolved by the following updated file for Windows 95, and later
versions of this file:

  SHELL32.DLL  version 4.00.951  817,664 bytes

To install this update, download the Windows 95 Service Pack 1 Update Setup.exe
file from one of the sources listed below.

In addition to correcting the problem described in this article, the new version
of Shell32.dll provides the ability to browse printers from the Add Printer
Wizard for users of the Microsoft Service for NetWare Directory Services (NDS).
Users of the standard network clients included with Windows 95 can already
browse printers and do not require this update to browse for printers.

Installation
------------

To correct the problem described in this article, follow these steps:

1. Download the Setup.exe file from one of the online services listed below to
  an empty folder.

2. In My Computer or Windows Explorer, double-click the Setup.exe file.

3. Follow the instructions on your screen.

4. After the installation process is finished, shut down and then restart your
  computer.

Instructions for Downloading
----------------------------

To obtain this file, apply Microsoft Windows 95 Service Pack 1. For additional
information about applying Microsoft Windows 95 Service Pack 1, click the
article number below to view the article in the Microsoft Knowledge Base:

  Q142794 Availability of Microsoft Windows 95 Service Pack 1

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Windows 95. This issue
is resolved in Microsoft Windows 98.

MORE INFORMATION
================

This problem does not affect most users, because copying a file onto itself is
an unnecessary task. In addition, this problem occurs only in the following
circumstances:

- The problem occurs only when you copy a file onto itself on a drive using
  drive mapping (such as a mapped network drive or a drive created with the
  SUBST command) or a UNC connection. Users in non-networked environments, and
  users who do not use the SUBST command, are not affected by this problem.

- The problem occurs only if you use two views of the same network resource, or
  drive created with the SUBST command, and copy a file onto itself. For
  example, the problem may occur if you map drive X to the
  \\<server>\<folder> network resource, map drive Y to the same
  network resource, and then copy a file from the root folder of drive X to the
  root folder of drive Y.

- The problem occurs only with files of a certain size. While preliminary
  testing indicates that only files smaller in size than approximately 234K are
  affected, the affected file size is also dependent on the size of the local
  and network buffers, and may vary based on configuration.

For additional information about issues resolved by updates to this component,
please see the following articles in the Microsoft Knowledge Base:

  Q161100 File May Be Truncated When Copied to a Full Network Drive

  Q150215 Disabling Automatic Network Shortcut Resolution

  Q138014 File May Be Truncated to Zero Bytes When Copied Onto Itself

  Q136834 Error Copying Read-Only Files to Core SMB Server


  Q160807 Cannot Connect to Windows NT Server with Many Shares


For additional information about Windows 95 updates, please see the following
article in the Microsoft Knowledge Base:

  Q161020 Implementing Windows 95 Updates


Additional query words: msnWin95misc pcweek servicepack1

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Keywords          : kbfile kbnetwork msnets win95 
Technology        : kbWin95search kbWin95
Version           : :

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