CPU randomly dropping while under load

[pl.killer.22911]

So I was approached by someone with a problem. It seems that the cpu is working completely fine at 100% load, then randomly the speed drops to 380 MHz and the utilization drops to 13%, then after a few seconds goes back to its previous speed and 100% utilization. Happens most during games. It doesn't seem to be a thermal issue, and everything is fully updated. It seems to occur after windows updates. This issue happened once before after a Windown 10 update, then they solved it, and now after another Windows update the issue came back and no one can remember how they fixed it. Any clues? This is an asus laptop.

 

[pl.killer.22911]

Using driver booster 5 seemed to fix the problem.