There is a small window that opened up on my desktop. It opened along with Windows when booting up.
Task manager does not show it as an open window:
Alt + Tab can switch focus to the window, but it does not have a title bar.
Windows + Tab does not see the window at all.
Visual Studio's Spy++ gives this information on it:
And finally, Process Explorer cannot find that handle given by Spy++.
How can I find out what process this window belongs to so that I can further investigate what it is?