Every minute or so, my computer freezes for 15 to 20 seconds, after which I can use the computer for another minute until it freezes again; this process makes the computer barely usable.

Windows 10 Home, Version 1803, OS Build 17134.254.
Dell desktop computer.
12 GB RAM.
64-Bit OS.

Steps I have taken:
1. I set priority to Low, but there was no change.
2. I ran Malwarebytes, SUPERAntiSpyware, AdwCleaner and CCleaner.
3. I disabled Superfetch and SmartByte Network Service.
4. I ran DISM /Online /Cleanup-Image /RestoreHealth.

Using Process Explorer and Resource Monitor, I discovered that the offending process is something called sechost.dll, which is a part of RpcSs, which is a svchost.exe process. Every minute or so, CPU usage of sechost.dll shoots up to 25% for 15 to 20 seconds.

I discovered that if I Restart the computer, the problem goes away for an hour but then slowly returns.

I’ve spent hours researching this problem, with no success.

I will try to attach screen prints.

Ideas or suggestions?

Thanks.