What if I got over-scan issue?

I am getting an over-scan issue.  The screen looks like the following:

A:

root cause: “overscan” issue is a popular issue for HDMI display. some TV and monitors provide the configuration to avoid it, but some do not. to avoid it, most of the devices, such as RaspBerry, WDTV…, provide a tool to allow users to adjust the display rect or ratio. we also provide such tool (preloaded). run setwindow in terminal to set screen position manually. Usage:

We can use the utility ‘$sudo board-config.sh’ to configure the screen percentage to solve the over scan issue.