Slow system log’s clearing

Hi everyone,
I’m writing from my Notebook, which has got a SSD and a clean installation of WIN10 64bit.
Yet, CCleaner has problems that I’ve never come upon all my life long since now: the cleaning process of the system log is very slow. Actually, my brother has the last version 5.36.6268 64bit on Windows 10 as me and his cleaning process is quicker.
What kind of issue is my problem provoked by?
Thank you all