Double-Clicking the Mouse Button Acts as a Single Click

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
Microsoft Windows NT Server version 4.0, Terminal Server Edition

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 latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

Dblclick-fix has been superseded by Getadmin-fix. For your convenience, the English version of this post-SP3 hotfix has been posted to the following Internet location. However, Microsoft recommends that you install Windows NT 4.0 Service Pack 4 to correct this problem.

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 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.

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 single click left handed

Keywords : kb3rdparty NT4SP4Fix kbbug4.00 kbfix4.00.sp4 nt32ap NTSrvWkst
Version : WinNT:4.0
Platform : winnt
Issue type : kbbug