Microsoft KB Archive/216570

{|
 * width="100%"|

-

The information in this article applies to:


 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Datacenter Server
 * Microsoft Windows 2000 Professional
 * Microsoft Windows 2000 Server
 * Microsoft Windows NT Workstation version 4.0
 * Microsoft Windows NT Server version 4.0

-

SYMPTOMS
Your computer may hang (stop responding) when it is searching for new hardware or when you connect a wheel mouse. The following information may also explain why the wheel portion of a wheel mouse does not function after an upgrade to Windows 2000. This is referring to an instance where a customer has never had the wheel functionality but hoped that the upgrade would enable it.

CAUSE
This problem can occur if either of the following conditions exists:


 * You attach a wheel mouse (Microsoft Wheel Mouse or third-party wheel mouse) to the PS/2 (IO8042) port. Your computer's Basic Input/Output System (BIOS) is not recognizing the methods used to identify the wheel mouse, and your computer hangs as a result.
 * You are using a serial switch box.

RESOLUTION
To resolve this problem, contact your computer's manufacturer to inquire about the availability of and updated BIOS for your computer.

To work around this problem, use one of the following methods:


 * Use a mouse that attaches to the serial port, or use a mouse that does not have a wheel.
 * Use the workaround described in the More Information section.
 * Do not use a serial switch box.

STATUS
Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.

MORE INFORMATION
When a wheel mouse is connected to your computer, a series of signals are exchanged at frequencies of 200 hertz (Hz), 100Hz, and 80Hz (in that order). This series of signals activates the mouse. To detect the type of mouse connected to the computer, another three-part sampling rate is sent consisting of the following frequencies: 20Hz, 40Hz and 60Hz. If the proper responses are given, a Plug and Play mouse ID is returned through a 7-byte scan code. This scan code consists of one of the following alpha-numeric codes:


 * MSH0001 - Standard two-button Microsoft mouse
 * MSH0002 - Microsoft Wheel Mouse
 * MSH0005 - Microsoft Track Ball Mouse

While these frequencies are technically within the specification for an IO8042 device, many programmers do not implement them. When no response is provided to this query method, no mouse ID is returned, and this process is repeated indefinitely.

As a workaround in Windows NT 4.0, the following registry key is added "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\I8042PRT\Parameters\EnableWheelDetection" with the WheelDetection value having one of the following data values:
 * 0 - The enabling code is never run, and the wheel never functions.
 * Any other number - The enabling code is always run.

Though the key remains the same, the possible data values for the WheelDetection value and the default value is different in versions of Windows NT 4.0 later than Windows NT 4.0 Service Pack 3 (SP3) and in Windows 2000. The WheelDetection value can have one of the following three data values:
 * 0 - The enabling code is never run, and the wheel never functions.
 * 1 - The querying code described earlier is run. If the signal sequence determines that a mouse exists, the enabling sequence is run.
 * 2 - The enabling code is always run.

There is a retail and an Original Equipment Manufacturer (OEM) version of the Microsoft wheel mouse. These settings affect Windows NT 4.0 SP3 and Windows 2000 differently. A data value of 1 is not recognized by the OEM version of the mouse, which means you need to set the data value to 2 in order for the wheel mouse to be recognized.

This problem is very rare and is most common with computers built before the introduction of the wheel mouse. Most manufacturers now identify the signaling method used to enable the wheel mouse. This problem can usually be resolved by upgrading the computer's BIOS to the latest version. Additional query words:

Keywords : kbenv kbhw

Version : WINDOWS:2000; winnt:4.0

Platform : WINDOWS winnt

Issue type : kbprb
 * }