I have noticed that when MsMpEng starts up, an svchost starts up and runs at 50% - it continues to run until MSE finishes its download and daily scan. My system spikes to 100% , especially if I am doing other work at the time. I have MBAM set to download and scan 1 hour after MSE so there is no clash there. My system has very low CPU usage on average - until MSE starts up. There is a setting in MSE 'limit CPU usage during scan' set at 50% - I thought that this meant that MSE would not start a scan if my CPU usage was 50% or above - so I have no need to change this, right? I have not seen this on W10, it is only happening on W7. Anyone else see this svshost at 50% CPU when running MSE ?