Windows – How to make a window active without having to click in it in Windows 10

There are several mouse registry settings from HKEY_CURRENT_USER\Control Panel\Mouse that might help you here :

MouseHoverTime : REG_SZ : hover time in milliseconds : 400 default
MouseHoverWidth : REG_SZ : hover width in pixels * 2 : 4 default (2 pixels)
MouseHoverHeight : REG_SZ : hover height in pixels * 2 : 4 default (2 pixels)

Width and height define the size of the hover rectangle, or in other words the number of pixels that the mouse can move and still be considered as hovering in-place. The hover-time specifies how long the mouse pointer has to stay in the hover rectangle before a mouse hover message is generated.

I have managed to duplicate some of your problems, and it seems to me that the "Single click to open an item" mode was really badly done by Microsoft, to select an item by just hovering over it. However, the behavior still looks consistent to me.

If you have changed mouse parameters, this might have had the effect of throwing off the mouse behavior.

My own preference is to counsel you to return all mouse parameters to the default and to turn off "Single click to open an item".

I also do not like double-clicking, but my solution was to program the wheel-click of my mouse as a double-click, this way achieving double-click via a single-click without monkeying with the mouse parameters. Microsoft software does not always work reliably with non-default parameters.

I'm pretty sure that the handling of mouse click activation is up to the application and is not configurable at a system wide level.

http://msdn.microsoft.com/en-us/library/hae1hxka.aspx