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You may be prompted to restart your computer when you disable and re-enable a USB mass storage device, or the Windows 2000 installation may fail if you try to install it by using a USB CD drive.

When you disable and then re-enable a USB mass storage device, you may be prompted to restart your computer.

Additionally, when you try to install Windows 2000 by using USB CD drive, your computer may momentarily lose its connection to the CD drive during the second part of the setup. The second part of the setup is the GUI mode setup, which is when the USB 2.0 controller driver is loaded. If your computer momentarily loses its connection to the USB CD drive during this time, the driver may not install correctly and Windows 2000 may fail to install.

Note This problem may also occur when you install an operating system over a virtual media connection.
This problem occurs because of a code defect in the Usbstor.sys file on Windows 2000. When you turn the device off, and then turn it back on, if there is a data toggle error, the driver should reset the pipe and start the enumeration afresh. Otherwise, the device is not enumerated correctly, and you may be prompted to restart the computer.

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.

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, submit a request to 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 tool in Control Panel.
   Date         Time   Version        Size    File name   ------------------------------------------------------   11-Jul-2003  00:26  5.0.2195.6773  21,584  Usbstor.sys
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Article ID: 823086 - Last Review: 10/27/2006 03:19:00 - Revision: 4.3

  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional Edition
  • Microsoft Windows 2000 Server
  • kbautohotfix kbhotfixserver kbqfe kbstoragedev kbddk kbbug kbfix kbqfe kbwin2000presp5fix KB823086