I have a strange problem with my Windows 7 environment whereby an active window will suddenly minimize for no reason.
Here is an exact example:
Working on a Word doc, I decide I need to do a small calculation, and open 'Calculator'.
The Calculator window appears as active window, sitting on top with the Word doc visible behind.
As I am typing my figures into Calculator, it suddenly minimizes. The only way to get around this is to minimize all windows, then bring up Calculator.
If the mouse pointer is resting anywhere over window (e.g. Calculator), it will not minimize as described. Only when pthe ointer moves off the window. Behavior is therefore as if I am clicking on another window (when I'm not).
Note: This happens with other apps, not just calculator. That was just an example.