WinFocusMon 1.0.0.0

Using this straightforward application you can select a window and monitor its state change, then you can explore the activity log

WinFocusMon (WFM) is a diagnostic utility used to monitor a specified window and determine why it loses input focus unexpectedly. WFM can notify the user when the state of the monitored window changes, as well as create a report with greater detail about the event.

WFM can monitor almost any application window, such as your word processing program, web browser, email client and even full screen games. If you have ever been typing along only to find that some of what you typed is missing, or were playing a game when all of a sudden it minimizes to the desktop or stops accepting input, WFM may be able to tell you why. What can happen is that another window, even though you never saw it, may have acquired keyboard focus, thus effectively hijacking keyboard and/or mouse input. When this occurs, WFM will try to provide information about the offending process, allowing you to take it up with the application developer or look for an alternative program.