DOCUMENT:Q276346 08-MAY-2002 [vbwin] TITLE :FIX: SendKeys Function Locks Keyboard on Windows 2000 PRODUCT :Microsoft Visual Basic for Windows PROD/VER::5.0,6.0,SP1 OPER/SYS: KEYWORDS:kbOSWin2000bug kbVBp kbVBp500 kbVBp600 kbGrpDSVB kbDSupport ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0, used with: - the operating system: Microsoft Windows 2000 SP1 - Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0, used with: - the operating system: Microsoft Windows 2000 SP1 ------------------------------------------------------------------------------- SYMPTOMS ======== When a Visual Basic program is running, the keyboard on your Windows 2000-based computer freezes. This problem can also occur if the application is hosted on a Terminal Server, and if the client is running Windows 2000. The following system event is logged on the Windows 2000-based computer: Event Type:Error Event Source:i8042prt Event Category:None Event ID:27 Description: The operation on timed out (time out is configurable via the registry). CAUSE ===== This problem is the result of a bug in the Windows 2000 keyboard driver, and only occurs in conjunction with the Visual Basic SendKeys function. RESOLUTION ========== To resolve this problem on a Windows 2000-based computer that is not running Terminal Services, install Windows 2000 Service Pack 2 (SP2) from the following Microsoft Web site: http://www.microsoft.com/windows2000/downloads/servicepacks/sp2/default.asp A supported fix is now available from Microsoft, but it is only intended to correct the problem described in this article and should be applied only to systems experiencing this specific problem. This fix may receive additional testing at a later time, to further ensure product quality. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows 2000 service pack that contains this fix. To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, please go to the following address on the World Wide Web: http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS NOTE: In special cases, charges that are normally incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. Normal support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this fix should have the following file attributes or later: Date Time Version Size File name ----------------------------------------------------------- 05/18/2000 07:17p 5.0.2195.2096 48,592 I8042prt.sys To unlock the keyboard manually, on the Start menu, point to Settings, and then click Control Panel. Click Keyboard, and then reset the Keyboard Refresh Rate. WORKAROUND ========== There are also two programmatic workarounds to this problem: Workaround 1: Replace the SendKeys function with the keybd_event API function as follows: Private Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte,ByVal _ bScan As Byte, ByVal dwFlags As Long, ByVal dwExtraInfo As Long) Const KEYEVENTF_KEYUP = &H2 Const VK_TAB = &H9 keybd_event VK_TAB, 0, 0, 0 keybd_event VK_TAB, 0, KEYEVENTF_KEYUP, 0 Workaround 2: Replace the Sendkeys function with the PostMessage API function as follows: Private Declare Function PostMessage Lib "user32" Alias "PostMessageA" _ (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _ ByVal lParam As Long) As Long Const WM_KEYDOWN As Long = &H100 Const VK_TAB As Long = &H9 Dim retVal as long retVal = PostMessage(Me.hwnd, WM_KEYDOWN, VK_TAB, 0) STATUS ====== Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. MORE INFORMATION ================ Steps to Reproduce Behavior --------------------------- 1. On a computer that is running Windows 2000, create a new Standard EXE project in Visual Basic. Form1 is created by default. 2. Set the Keypreview property of Form1 to True. 3. Add six TextBoxes to Form1. 4. Add the following code to the General Declarations section of Form1: Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer) If KeyCode = 13 Then SendKeys "{tab}" End If End Sub 5. Run the project. 6. Press and hold down the Enter key on the numeric keypad, and note that the keyboard locks in approximately five seconds. For additional information, click the article number below to view the article in the Microsoft Knowledge Base: Q262798 PS/2 Keyboard/Mouse Not Recognized When Plugged Into Running Computer Additional query words: stops responding key pad board ====================================================================== Keywords : kbOSWin2000bug kbVBp kbVBp500 kbVBp600 kbGrpDSVB kbDSupport Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 Version : :5.0,6.0,SP1 Hardware : ALPHA x86 Issue type : kbprb Solution Type : kbpending ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.