Weird Sneaky Lag

[MrSuper]

I've recently started to experience very unusual lag using my PC. It randomly starts and randomly stops. But what I've noticed is that when it is happening, and I open task manager to see what is going on it immediately stops. Like it's trying to hide. Therefore, I've ran anti-malware bytes and anti-virus, it found some things but not what is causing this. There is no pattern to when this lag occurs. My system is pretty new.

 

Specs:
i7 8700k (no oc) - Cooler Master Hyper 212 cooler

Gigabyte Z370 Ultra Gaming MB

G.SKILL TridentZ RGB (8x2) 2400mhz

ASUS 1070 STRIX

Samsung 850 SSD 250gb

1TB WD Blue

Corsair CX750M (due to be upgraded)

 

I've attached a video of the lag. Notice when I close task manager, it begins.

lag capture resized.mp4

[will2135]

Any windows updates? make sure everything is updated.

[MrSuper]

11 minutes ago, will2135 said:

Any windows updates? make sure everything is updated.

So yes. There is updates. But it's broken. 

The above update (v.1709) I've downloaded and tried to install multiple times. For some reason, it never gets updated. I restart my computer, but the update remains to be installed. Then it redownloads it.

[MrSuper]

I've now restarted 5 times and it still tells me to restart to finish installing the same update.