Infinite loop occurs when the serial port is unexpectedly removed on a Windows 2000-based computer

This article was previously published under Q328468
This article has been archived. It is offered "as is" and will no longer be updated.
If you disconnect a serial port while the serial port driver is reading data from a universal asynchronous receiver-transmitter (UART)-based serial device, the standard Microsoft serial port driver can enter an infinite loop in its interrupt service routine on a Microsoft Windows 2000-based computer.
You may receive the following Stop error:
-1: kd> .bugcheckBugcheck code 000000CAArguments 00000003 8b06c670 e25933c8 000000011: kd> kChildEBP RetAddr f6853c2c 80424be6 nt!IopProcessNewDeviceNode+0x89f6853c3c 804b7da4 nt!IopProcessNewChildren+0x22f6853c60 804b7b8f nt!IopEnumerateDevice+0x20af6853c9c 804b798a nt!IopStartAndEnumerateDevice+0x1c3f6853cbc 804be655 nt!IopProcessStartDevicesWorker+0x72f6853ccc 804b796d nt!IopForAllChildDeviceNodes+0x1ff6853cf0 804b78bb nt!IopProcessStartDevicesWorker+0x55f6853d0c 804b7860 nt!IopProcessStartDevices+0x43f6853d30 80424a8f nt!IopBusCheck+0x78f6853d78 80416f53 nt!IopDeviceActionWorker+0x40ff6853da8 80454fde nt!ExpWorkerThread+0xaff6853ddc 8046a302 nt!PspSystemThreadStartup+0x5400000000 00000000 nt!KiThreadStartup+0x16
This problem occurs when a serial port is removed from the computer while the computer is running. The serial port driver performs a test loop until the Line Status Register clears its Read bit.

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 do not have to restart your 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) 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--------------------------------------------------------------21-Sep-2003  00:36  5.0.2195.6824      14,160  Serenum.sys21-Sep-2003  00:35  5.0.2195.6824      60,880  Serial.sys
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section of this article.
For additional information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
816915 New file naming schema for Microsoft Windows software update packages
824684 Description of the standard terminology that is used to describe Microsoft software updates
serial port

Article ID: 328468 - Last Review: 10/26/2013 17:30:07 - Revision: 2.6

Microsoft Windows 2000 Server, Microsoft Windows 2000 Professional Edition, Microsoft Windows 2000 Advanced Server

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