Your solution seems unnecessarily complex for this problem. The problem the OP describes is easily worked around by:
- Go to Control Panel\All Control Panel Items\Performance Information and Tools\Advanced Tools
- Click on Adjust the appearance and performance of Windows
- Under the 'Visual Effects' tab, uncheck the "Enable Aero Peek" option.
- Apply or click OK.
But this is just a work around. Aero Peek is a nice feature but this work-around disables it completely.
The answer provided by kotpierdzibonk actually addresses the cause of this:
- Open task manager.
- End the process 'sidebar.exe'.
Doing this should allow Aero Peek to function in a reasonable way. However, now you don't have gadgets anymore..
This is surely a bug with Windows that apparently has not been addressed in over two years. The source of the bug seems to be a clash between SideBar and Aero Peek. It likely will never get fixed either, so I guess you must decide between SideBar and Aero
Peek, or just live with the intolerably annoying guess-work to figure out which windows are open after the alt-tab window gets hidden by a preview window..