Assuming you would like to know how to fix your computer display so that it is no longer overlapped by another display, there are a few potential solutions.
First, you could try restarting your computer. This will often fix minor glitches like this. If that doesn't work, or if the problem persists, you could try adjusting your computer's resolution. To do this, go to the Control Panel and find the Display settings. From here, you can change the resolution of your display. Try setting it to a lower resolution first; if that doesn't work, you can try increasing the resolution until the problem is fixed.
If neither of these methods works, there may be an issue with your graphics card drivers. You can check for updates by going to the manufacturer's website (e.g., NVIDIA or AMD) and downloading the latest drivers for your card model. Once downloaded, install them and restart your computer; this should resolve any driver-related issues causing your display overlap problem.