I think I found out the root of the problem. For whatever reason, it's Minecraft. Yeah, whenever I launch & quit, fullscreening a YouTube video on Firefox just confuses Windows Explorer. That's really odd, because on my main computer (a late 2013 iMac) running Windows 8.1, nothing happens. So, mystery solved. And I'll admit, I think I used the wrong version to you-know-what.
WEATHER UPDATE
Actually listening to that version, it's a very good mix.