I was working happily, remoted into a Win7 administrative machine which happened to have the VMware client installed upon it. And, inexplicably, I noticed that my task manager window was barren of both tabs and menus. I had no idea what happened, expected it was a memory probable of some sort, so rebooted the machine. To my surprise, after logging back into it, the same behavior was experienced. I could see active processes or expand the scope to include other users. What had happened to Task Manager in this installation of Microsoft Windows?
Well, it turns out that I must have double-clicked accidentally on the exterior border of the Windows Task Manager (for instance on the red circle in the screen shot). I was able to return things to normal by double-clicking again on this exterior border. In fact, try it for yourselves, you can toggle between having tabs + menus and removing them by double-clicking on the window border. “When was this feature added to Windows?”, I wondered.
So, I got distracted and started up several other VMs, and found that this behavior is present on Windows 2008, Windows 2003, Win 8.1, Win 7, and Windows XP. In other words, this behavior has been in Windows for a very long time, and I have simply never noticed it before. Just goes to show, you learn something new every day!