Defender keeps turning itself on

[Spork829]

"Antimalware service executable" is CONSTANTLY running on my laptop, and since it's a pretty old, weak machine, it gets up to around 40% CPU usage. It also seems to take up about 2GB of space when it's running, and is constantly writing to my SSD. Not ok. So I went into settings and disabled Windows defender's real-time protection, which fixed the issue. The exe is still running but no longer using more than 2% of CPU and not writing to the disk. Also the 2GB of storage it was taking up magically reappeared when I turned this off. 

 

After a few days, however, I booted up the laptop and noticed it had turned itself back on. It's done this several times since: Taking up CPU and disk usage again, as well as that random 2GB of space. I basically have to go in and turn it off once every 3-5 days. Does anyone know a fix so I can ACTUALLY PERMANENTLY disable this garbage?

[Spork829]

It's also notifying me like every 3 seconds that my PC is now unprotected, would be nice if I could get rid of that as well.

[HarryNyquist]

If you're using windows 10 you have to use Local Group Policy/the Registry to disable it. Using the settings app ensures it'll just turn itself back on after "a while." In the group policy editor (Pro only) it's under Computer Configuration>Administrative Templates>Windows Components>Windows Defender, and toggle "Turn Off Windows Defender" to "Enabled" and restart.

 

The registry key is under HKLM\SOFTWARE\Policies\Windows Defender. Add a DWORD (32-bit) value of "DisableAntiSpyware" set to 1. If this option is already there, just update it instead of adding it. Restart afterward.

 

Note that I haven't personally tested the registry hack so I don't know if that'll work for you, if you don't use Windows 10 Pro. I'm not sure about disabling that notification though (You really SHOULD have some kind of antivirus running, honestly)