Hi Jacqueline.
Could you share a screenshot of the white box?
Does it appear when AVG Internet Security user interface is open on your screen?
In the past week, a white square has appeared on my monitor. When I press CTRL ALT DEL to see what else is running, it is only my AVG subscription. When I cancel that, the white square disappears. It is so aggravating. I am running Windows 10.
Thank you for letting us know, Jacqueline.
If you need anything else, do not hesitate to let us know.