A combo box control selects an unexpected value in Windows 7 SP 1 or Windows Server 2008 R2

Van toepassing: Windows 7 Service Pack 1Windows 7 EnterpriseWindows 7 Professional


Consider the following scenario:
  • You have a computer that is running Windows 7 Service Pack 1 (SP1) or Windows Server 2008 R2. 
  • You have a Windows Form application that contains a combo box control and other controls on the computer.
  • The combo box control is put on a form and populated with a list of values. For example, the combo box control is populated with the following values:
    • a0 
    • a1 
    • a2 
    • a3 
    • a4 
    • a5
  • The DropDownStyle property is set to DropDownList, and the AutoCompleteMode property is set to Append or to SuggestAppend.
  • You follow these steps:
    1. You click the combo box control by using the mouse. A drop-down list appears.
    2. You type a4. This highlights the correct item in the list.
    3. You press the Tab key to move the focus to the next control.

In this scenario, the combo box control selects a0. However, you expect the control to select a4.


This problem occurs because the index of the selected item is reset when the control loses the focus.


Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, go to the following Microsoft website: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.


To apply this hotfix, you must be running Windows 7 Service Pack 1 or Windows Server 2008 R2 Service Pack 1 .

Restart requirement

You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any previously released hotfix.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


See ComboBox Class for information about the Windows combo box control.

See the terminology Microsoft uses to describe software updates .