PnP Serial Device May Not Enumerate on a Computer That Is Running Windows Me (297125)


The information in this article applies to:

  • Microsoft Windows Millennium Edition
This article was previously published under Q297125
If this article does not describe your hardware-related issue, please see the following Microsoft Web site to view more articles about hardware:

http://support.microsoft.com/default.aspx/w98?sid=460

SYMPTOMS

A serial PnP device that is attached to a serial port may not be detected when Windows Millennium Edition (Me) starts. This prevents Windows Me from automatically finding and installing the appropriate driver for the device.

CAUSE

This issue can occur if the PnP Serial device issues a BREAK condition after sending the PnP identifier string to the host. The Windows Me version of the Windows serial PnP bus driver (the Serenum.vxd file) interprets this BREAK as an error condition, and therefore terminates enumeration of the device.

Earlier versions of the Serenum.vxd file do not check for error conditions after the serial PnP identifier string is received from a device. This is not true for Windows Me, which does check for errors after receiving the PnP identifier string.

RESOLUTION

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that are experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone 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 fix should have the following file attributes or later:
   Date       Time         Version     Size     File name     Platform
   -----------------------------------------------------------------------------
   05/04/01   05:03 P.M.   4.90.3002   13,047   Serenum.vxd   Windows Millennium

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

For additional information about Windows Me hotfixes, click the article number below to view the article in the Microsoft Knowledge Base:

295413 General Information About Windows Millennium Edition Hotfixes

Modification Type:MajorLast Reviewed:7/13/2006
Keywords:kbHotfixServer kbQFE kbbug kbfix kbHardware kbQFE KB297125
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