Double-Clicking the Mouse Button Acts as a Single Click

 Last reviewed: February 23, 1998
Article ID: Q170510
The information in this article applies to:
  • Microsoft Windows NT Workstation version 4.0 Service Pack 3
  • Microsoft Windows NT Server version 4.0 Service Pack 3

SYMPTOMS

Double-clicking the mouse in your application behaves as if you clicked the mouse button once. This behavior has been observed in the following applications running in Windows NT 4.0 Service Pack 3:

  • Visio Professional 4.x

CAUSE

Windows NT 4.0 Service Pack 3 adds a code path where mouse movement does not update the timestamp for a WM_MOUSEMOVE event. This behavior can potentially occur with any application that relies on WM_MOUSEMOVE timestamps. For example, Visio uses a custom event handler to detect double-clicks rather than checking for the WM_LBUTTONDBLCLK message.

RESOLUTION

To resolve this problem, obtain the hotfix below, or wait for the next service pack.

Dblclick-fix has been superseded by Getadmin-fix. You can find the latest hotfix at the following Microsoft ftp site: 

   ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/
   hotfixes-postSP3/getadmin-fix
You can find the original hotfix at the following Microsoft ftp site: 

   ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/
   hotfixes-postSP3/archive/dblclick-fix
WARNING: If you install the original (archived) version of this hotfix AFTER you apply the later version, your system may become unusable. Microsoft does not recommend you install the original hotfix after applying the later version.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0. A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information. receive

MORE INFORMATION

Visio Professional is manufactured by Visio Incorporation, a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.

Additional query words: 4.00 prodnt single click left handed
Keywords : kbbug4.00 kbfix4.00 nt32ap NTSrvWkst kb3rdparty
Version : 4.0
Platform : winnt
Hardware : ALPHA x86
Issue type : kbbug
Solution Type : kbfix

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Last reviewed: February 23, 1998
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