If the damaged area is along the borders of the screen,
you could use the donationware
DesktopCoral :
DesktopCoral is an unusual program designed to "reserve" some portion
of your desktop which is shielded from maximized applications..
Essentially, it acts like an invisible resizeable docking bar, which
can be docked to any side of your desktop. This invisible dock acts as
a barrier to maximized applications and essentially shields this area
of your desktop from other applications.
Within this shielded area you might put certain application windows
that you want to be always visible, or you might put one of the many
desktop tools like a calendar or system information component.
The app creates a floating window that you need to drag to the
damaged area.
As you might not be able to interact with that part of your screen,
you might need to start it with command parameters.
According to the Help file of the application (DesktopCoral.chm),
the call might look like the following in order to reserve the
top 200 pixels of the screen:
DesktopCoral.exe -placement top -dockheight 200
To dismiss the app, right-click its area and select "Exit"
(or kill it from the Task Manager).