Cover Windows is a very small Windows application that allows users to cover part of any visible window. You can also use it to cover the entire desktop if that is needed. By covering a window or part of a window, you can hide sensitive information from that area or you can make it impossible to use various controls from that area.
According to the developer, one of the uses of this application is to hide the close button of any window (the X button near the top-right corner) so that we can avoid accidentally clicking on it. This is actually very smart idea specially for the laptop users as the touchpad sometimes makes the mouse cursor jump to unexpected places on the screen and clicking in unwanted places often results in annoying situations.
Cover Windows is a portable application but requires Microsoft Visual C++ 2010 runtimes to be installed. You can quickly install all the missing Visual C++ runtimes in Windows from the instructions on – How to Install all VC++ Runtimes Easily.
Cover Windows shows in a small window and assigns the C and D keys for its own use which can be annoying. When you press C, it will generate a new cover window that always stays on top of the selected active window. Similarly, you can press D to destroy these cover windows. The cover windows are very small by default but they can be resized.
All during this time, if you try to type in any other program with your keyboard then you will find C and D keys are not working because of Cover Windows. As soon as you close Cover Windows, this problem goes away. But if you close Cover Windows, it will also destroy all the windows that it has created.
You can download Cover Windows from https://windowsportableapps.blogspot.com/2020/05/cover-windows.html.