To address this problem, you’ll need to open up the Registry Editor and modify the value data of the DisableAntiSpyware key. The antiSpyware function is ON – According to a lot of Windows 10 community insiders, this problem might be caused by a Registry key that remains disabled despite the fact that Windows Defender is no longer the active antivirus.In this case, you will need to forcibly turn off Windows Defender – either via the Local Group Policy Editor or via Registry Editor. This usually happens when you’re using a security solution from a smaller company that is not yet verified by Microsoft. Windows Defender is overlapping – As it turns out, another scenario where you can expect this issue is when Windows Defender is actually overlapping another 3rd party antivirus that is currently active.To address this issue, you’ll need to use the Task Scheduler to tone down the frequency of the task that summons the MsMpEngprocess. The task frequency of MsMpEng is too high – According to a lot of affected users, a frequent reason why you’ll end up seeing this behavior is when an administrative task related to MsMpEng runs at very frequent intervals.In this case, you can either use a 3rd party repair utility to get the issue fixed or you can go for a repair install. File corruption affecting Windows Defender – One of the first scenarios that you should troubleshoot against is a scenario in which the reason why you are seeing this massive CPU usage is due to some type of corruption affecting the Windows Defender component.

Msmpsvc microsoft antimalware service