CPU Usage 100% ?

CPU Usage got stuck on 100% (right now, going on 15 minutes), but I cannot see which process it is.
This is listed as CPU decreasing.
Probably, if I restart, it will go away; I am just posting to learn that if there is anything could be causing this or it is just a temporary thing happened because of who knows what.
(In the username, my username was written in all processes, erased it with paint;don't get confused with that).
(And yes, with CPU 100% stuck; Firefox, Snipping Tool, Paint, Windows Explorer, and Control Panel is open and I can type this)

Try resource monitor, CPU tab,

Resource Monitor

Thank you.
I will use that next time.
I was using task manager start at start up, probably I will use resmon to start at start up after I check.

You're welcome, that's a more informative tool.