Simon Zerafa (Status: 
😊)If you are running Windows 10 or 11 and need a quick CPU stress test or to check system thermals and fan respose then you can use Windows Defender to do this.
If you perform a customised scan of your OS install drive with WD then it will use all cores and threads to check the drive.
For the few minutes this might take it will stress your system quite nicely! 😉🤷♂️