If you use the On-Screen Keyboard (Osk.exe) on a Windows XP-based computer, you notice that the On-Screen Keyboard behavior does not mimic the physical keyboard behavior in the following scenarios.
When you press the nlk key on the On-Screen Keyboard, the system does not send the KEYEVENTF_EXTENDEDKEY flag as expected.
Note The nlk key corresponds to the NUM LOCK key on a physical keyboard.
When you press 5 on the numeric keypad of the On-Screen Keyboard, and the NumLock key state is turned off, the system does not send the VK_CLEAR event as expected.
This behavior may affect some applications that use keyboard flags or keyboard events.
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 this specific problem.
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, submit a request to 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, visit the following Microsoft Web site:
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 have Windows XP Service Pack 2 (SP2) or a later service pack installed.
You do not have to restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace any other previously released hotfixes.
To use this hotfix, you do not have to make any changes to the registry.
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
Windows XP SP2, x86-based versions
Windows XP SP3, x86-based versions
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the On-Screen Keyboard, visit the following Microsoft Web site: