It seems that it’s not very well-known on how to undo a Minimize All or Show Desktop, two operations I briefly discussed yesterday.
To undo a Minimize All, you can right-click the taskbar and select “Undo Minimize All”, or at least you used to be able to do that. Minimize All is no longer on the menus, presumably because it ended up being redundant with Show Desktop.
So after you do your ÿ+M to Minimize All, you can use ÿ+Shift+M to undo Minimize All.
To undo a Show Desktop, just click Show Desktop again. If you used the keyboard accelerator ÿ+D, just press it a second time.