High Disk Usage

For the past few days my disk usage randomly goes up to 99-100%. It's noisy and slows everything down and is very annoying. There do not appear to be any processes taking up the disk space and I can't figure out what is causing it. Then sometimes it goes back down to normal and everything is fine. I have run malware scans and that didn't help. Here is what I have:

Windows 10 Home
3.80 gigahertz AMD FX-4300 Quad-Core
8 GB memory
Hitachi HDS721010CLA332 [Hard drive] (1000.20 GB)
NVIDIA GeForce GTX 750 Ti
I use Comodo Internet Security

What else do I need to check when this happens to figure out the cause?

 

Don't you mean CPU usage?
Open Task Manager, check Show processes from all users, and check what process is hogging the CPU.

 

In the task manager there is CPU, memory, disk, and network usage. It's the disk usage that is going up. And as I said in my post, when it happens there do not appear to be any processes hogging it. There are usually 3 0r 4 things that show disk usage but they are running at 0.2 to 0.3 MB/s. I don't see anything there that seems to be high.

 

Take a snapshot and upload it.

 

It isn't happening right now but the next time it does I will screenshot it and upload it.

 

This was after my computer had been sitting idle for hours. I came to turn it off and the disk was full. I had done things on it all day earlier without it happening. Sometimes it happens when I am doing stuff, though. It just seems very random.

 

That image shows a speed of 1.1 MB/s.
It has nothing to do with the disc being full.
Right-click your C drive, click Properties and you'll see how 'full' the disc is.
Hopefully another member can shed some more light on exactly what that 100% means.

 

That looks like a false positive, all the disk throughput listed there wouldn't stress a 2GB USB 2.0 thumb drive, even an older 5,400 RPM hard drive would be capable of 40 - 60MB/s.

The tool doesn't 'know' what your drive is capable of, it only shows 100% of current activity. When the slowdowns happen, it's probably Comodo fighting with Windows Defender or some 'bad' driver causing high kernel CPU activity.