I've been trying to kill the msmpeng.exe process using an elevated command prompt and a batch file launched as SYSTEM, but every time I attempt it, I get "Access is denied" in the output file. I've got Tamper Protection turned off in Windows Defender. Is there a trick to successfully restarting this process? I just need to clear out the memory it's consuming and don't plan to disable it permanently.
5 Answers
Another thing to consider is that SYSTEM isn't even the highest privilege. There's a group called TrustedInstaller that has even more authority. There are methods to gain that privilege temporarily, but they can be risky if you're not careful about how you implement them. Just a head's up: messing with it on a work system could trip security alarms.
Yeah, that's what I'd be wary of too. Unless you have a clear understanding of what's involved, it’s best to avoid those methods.
From my experience, the best approach is to monitor what triggers Defender to go into overdrive. If there are no clear patterns, it might be worth looking at reducing the frequency of scans or adjusting your settings until you find a balance that works better for your needs.
The msmpeng.exe you're dealing with is part of Windows Defender, and it's designed to resist being killed for security reasons. Your batch job sounds like a work-around, but it’s worth noting that high memory usage from Defender isn’t uncommon. If it's consistently using a GB, it might be worth checking for any on-demand scans or other processes interfering with it.
Right, and keeping in mind that Windows Defender runs at a kernel level, it’s naturally protected from being easily interrupted.
If it’s using this much memory, it could be trying to handle heavier tasks or scans, but I’d suggest checking if there’s a specific trigger causing it.
I get your frustration. You’re right to want control over what runs on your machine! Unfortunately, the responses you’re getting reflect a common opinion about not messing with processes like Defender, but I understand wanting to manage your system performance.
You’re hitting a wall because the process is shielded by design. Even running as SYSTEM, you can’t easily kill it since it's structured to resist that. It’s usually stable, sitting around 200MB unless something is triggering it excessively. Check Microsoft’s support posts on high RAM usage for Defender; those insights can sometimes help diagnose issues.
Totally agree. Debugging and trying to re-parent processes can be tricky and lead to further issues down the line.