Error message when you use a network connection to copy a large file from one Windows Vista-based computer to another Windows Vista-based computer: "The connection has been lost"


When you use a network connection to copy a large file from one Windows Vista-based computer to another Windows Vista-based computer, you may receive an error message that resembles one of the following:

Error message 1

The connection has been lost.

Error message 2

There is a problem accessing shared folder path.
Make sure you are connected to the network and try again.
This problem may occur if the following conditions are true:

  • The network connection is slow or is prone to errors. For example, the network connection uses long-distance, slow-wired links or modems. Or, the network connection uses a wireless 802.11 or Bluetooth connection, and the network signal is weak. For example, the wireless network signal may be weak because of the distance from the access point or because of interference. The problem may also be affected by network traffic, by network retries, by packet losses, or by other factors that affect reliability of the connection.
  • The file that is being transferred is large. For example, the possibility of experiencing this problem is proportional to the size of the file that is being copied. For example, you may experience the problem when the file is approximately 100 megabytes (MB) or larger on an 802.11b 11 Mbps wireless network.


This problem occurs because, in some scenarios, Windows Vista may not retry the connection. Instead, the connection is dropped. When this problem occurs, the file transfer is not successful.


Service pack information

To resolve this problem, obtain the latest service pack for Windows Vista. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
935791 How to obtain the latest Windows Vista service pack

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.


No prerequisites are required.

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 Vista, 32-bit versions
File nameFile versionFile sizeDateTimePlatform
Windows Vista, 64-bit versions
File nameFile versionFile sizeDateTimePlatform


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 Windows Vista Service Pack 1.