So I’ve had this weird problem ever since I got this Packard Bell laptop. Usually it’s fine, but occasionally I experience these really bad artefacts on web videos, like this:

There are several ways in which it’s kinda weird:
*It’s not every video, even when those videos are on the same site. I can’t really figure out a pattern to which videos it’ll happen to, but some sites seem to get it more often.
*Even on videos where it is a problem it’s not always the whole video. Quite often it starts doing it late on in the video.
*It seems to be the same bits of each video that have the problem, reloading the video doesn’t fix it, nor does skipping back and forth through it.
*Sometimes just part of the screen is affected, like above, sometimes it’s the whole screen; overall it looks like the video has been encoded really badly, except that’s not the case.
Any ideas? Oh, by the way, the graphics on this are nothing special, it’s just on-board Intel HD Graphics.
Thanks!