Question Event Viewer

[Brikic]

Like almost every hour my pc starts to lag and my pc makes a weird noise. It's not loud or buzzy its a wriggly noice kinda. But ive checked the event viewer and i pinned the time it happen. And by the time i found in security (Event Viewer) that someone has logged on to my PC. What could be the problem?
I have a desktop PC. HP Omen (Gaming pc)

 

[rgd1101]

malware scan your system?

 

[Brikic]

malware scan your system?

Done a full scan, no malware detected. I'm not sure if it's a person or if it is a client. It happens 50% of the times i start steam after reboot. It also just happens randomly

My pc just stops and makes a noise for a couple of seconds