@xxJackxx : Just three things you need to do. 1 - Make sure both cloud options are enabled in Windows Defender. 2 - Enable PUA detection : In HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\MpEngine add DWORD MpEnablePus with value 1. Reboot. 3 - Then start system maintenance and go have dinner. Windows Defender will do it's initial scan and build it's cache. When finished, you should no longer feel it having any impact on system performance.