Artifacts on the screen. What to do?

Question

Video cards

Large artifacts appear on the screen. If you change the background (for example, switch from a white browser to a gray background) or play with the mouse, it disappears; if this is not done, it may stand for several minutes. There used to be artifacts too, but I didn't pay much attention to them as they were small, only a few pixels, and appeared in 3-4 places at a time. The computer was not even a year old. Because of what it can be?

Answer 1

Because of what it can be?

Due to defective monitor or defective video card.

What to do?

Connect the monitor to another computer and observe the work.
Install another video card.