I am using Windows 10. For a few days now, this keeps happening, even after a few restarts.
There is a window, slightly larger than the default size of cmd, that appears for less than a second, about once every hour. It shows up, but doesn't stay long enough for a name to appear (even if it did, I wouldn't have the time to read it), or for any content (except for the white background) to show up.
This reminds me a lot of C# Console programs lacking any sort of Console.ReadLine() or Console.ReadKey(), that show up and disappear instantly when debugging.
I can't find anything out of the ordinary in the processes (including background and "show processes for all users".
The window is mostly annoying because it takes away my current focus, because as would most pop-ups do, it seems to take focus when appearing, then I have to refocus in what I was doing. This is particularly annoying in some games, like Starcraft II, where the pop-ups forces me out of the game, and I have to alt-tab back in, and that can hurt a match a lot if the timing is bad.
I'm looking for a way to identify which program is creating this window (maybe it's a virus, maybe it's just a bug in something on my computer), in the hopes of figuring out how to stop it.