Coming back to this matter, as I can guess reason of temporary freezing at
100 % CPU use.

There is an application which I deem very good, but at the same time very "
heavy ", which is taking a bunch of memory.

I am referring to Spy Doctor.

They are, under my point of view, fantastic, with daily updates,
demonstrating their work and interest with user clients.

However, much of freezing times is due to some of its operations in
background, which I was able to detect in tab Processes / CPU.

Generally, when such application is loaded and computer freezes by 100 %
CPU, they are in the top.

May be I am mistaken and there is only a coincidence. May be not.

That's all for time being.