Microsoft KB Archive/262798

= PS/2 Keyboard/Mouse Not Recognized When Plugged Into Running Computer =

Article ID: 262798

Article Last Modified on 1/27/2007

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APPLIES TO


 * Microsoft Windows 2000 Service Pack 1
 * Microsoft Windows 2000 Service Pack 2
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Service Pack 1
 * Microsoft Windows 2000 Service Pack 2

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This article was previously published under Q262798



IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry



SYMPTOMS
If a PS/2-style keyboard and/or Mouse is not connected to the computer before Windows 2000 startup, the keyboard is not recognized if you connect it later.



RESOLUTION
To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English version of this fix should have the following file attributes or later:

  Date         Time       Version         Size     File name -  02/04/2002   10:19 AM   5.0.2195.4900   48,720   i8042prt.sys

When you install this hotfix by using the hotfix package, the following registry items are created and set to add &quot;hotplugging&quot; capability:

Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\i8042prt\Parameters

Value: Headless

Type: REG_DWORD

Data: 0x1 (Allow hotplugging a PS/2-style keyboard. To disable this feature, set the data value to 0.)

This hotfix was updated on 2/4/2002. The updated hotfix also prevents the following error messages from appearing in the event log when you detach a USB keyboard:  

Type: Warning

Source: i8042prt

Event: 32

Description: The keyboard device does not exist or was not detected.

Type: Error

Source: i8042prt

Event: 26

Description: Exceeded the allowable number of retries (configurable via the registry) on device.



WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

If you need to log the error messages, change the value of the ReportResetErrors value in the following registry key to 1:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\i8042prt\Parameters

NOTE: This feature is highly dependent on the computer's BIOS. Because PS/2 hotplug is not in the PS/2 specification, some PS/2 controllers may not correctly handle &quot;hotplugging&quot; of a device, and some may short out devices. This new driver does nothing special to accommodate hotplug other than ignore initialization errors.

NOTE: This hotfix also corrects a problem that causes the operating system to stop responding on a Dell PE2550, which uses a USB keyboard.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows 2000 Service Pack 3.



MORE INFORMATION
For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base:

265173 The Datacenter Program and Windows 2000 Datacenter Server Product

For additional information about how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base:

296861 Use QChain.exe to Install Multiple Hotfixes with One Reboot

Additional query words: kbBaseOS

Keywords: kbbug kbfix kbwin2000presp3fix kbqfe kbwin2000sp3fix kboswin2000fix kbhotfixserver KB262798

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