Alt+Tab (switch between open programs) - might help change the focus
Windows 10 has an advanced version of ^ as I understand, which uses the key combo: Win + Tab. The cycle of these commands can be reversed by adding "shift" to the mix (in case of many open programs / windows and you dont want to cycle through all of them)
Win+x has different, but equally useful menus for win 8 / win 10 - I was overjoyed when i first discovered this, as it retired many many other shortcuts I used over the years. (to get to device manager / control panel / event viewer)
and if all else fails: Alt+F4 - closes active (focused) program / window. If no programs or windows are in focus, then it will bring up the "shut down" dialog box, which allows for reboot / signout / shutdown / Switch user / sleep and hibernation if its enabled.
In later versions it's pretty common to see such windows that don't actually have focus. Clicking again on the title bar usually fixes the problem but I find it very annoying. There's a race condition in the system somewhere that Apple doesn't recognize as a bug.