Cover Windows is a portable tool that will permit you to cover sections of any window with other windows.
Cover Windows is a simple tool that allows you to block a portion of an active window with a blank window - the newly created blank window is moveable. A tool such as this will come in handy when you want to obscure the Close button of any window preventing users from accidentally clicking on that button, for instance.
You will need a program like Winzip to unpack and use Cover Windows. Its UI is straightforward and resides in the systray when not in use. All commands can be performed from the interface, or you can use the predefined keyboard shortcuts.
This is the initial release of this app; perhaps in the future, the authors could add the ability to size the blank window and also allow for adding text inside.