A window that has the WS_EX_TOPMOST extended window style removed is displayed above other windows

Applies to: Windows Server 2012 R2 DatacenterWindows Server 2012 R2 EssentialsWindows Server 2012 R2 Foundation


Consider the following scenario:
  • You run an application that creates a topmost window by using the WS_EX_TOPMOST extended window style on a computer that is running Windows 8.1 or Windows Server 2012 R2.
  • The application calls the SetWindowPos function together with an hwndInsertAfter parameter whose value is set to HWND_NOTOPMOST in order to remove the WS_EX_TOPMOST extended window style from the window.

In this scenario, the window that no longer has the WS_EX_TOPMOST extended window style may be displayed incorrectly above other windows that have the WS_EX_TOPMOST extended window style.


Update information

The fix for this problem is included in security update 3002885 . This update is dated November 11, 2014.


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


Learn about the terminology that Microsoft uses to describe software updates.