Hey there, @MiloshDr!
It looks you might want to disable some Windows Services to check if it would resolve the issue with the HDD usage spikes!
Press Windows+R > Write services.msc
Disable
1-Super fetch
2-Background Intelligent Transfer Service
3-Windows Search
If that doesn't help you, then you should definitely consider running some anti-malware software to check your computer. I'd also consider defragging your HDD and checking its health and SMART status using
its brand-specific diagnostic tool.
Keep me posted with the troubleshooting!
SuperSoph_WD