Back in Windows 7, when one presses alt+tab the "Windows Flip" menu appears and if (s)he holds alt but stops pressing tab, a preview of the app appears. In Windows 10, the behaviour is different: the menu looks different (not sure if it can be still refered as "Windows Flip") and holding alt without pressing tab doesn't bring the preview. While I'm ok with the menu itself, I wonder if there's a way to bring the preivew back.
The problem is also described here; let me bring the screenshot from there to illustrate what preview I'm talking about:
(I add the windows-7 tag so that gentlemen familiar with its internals may help too)
PS As mentioned in comments, Aero Peek works for me for previewing desktop (when cursor hovers over bottom right corner thing on TaskBar); and also works with elements on TaskBar (hover mouse over an element → get a smaller preview; hover mouse over that preview → get full window preview which is what I miss when using alt+tab).