How to disable Antimalware Service in Windows 10 Home.?

Hi
I’m working as a 3D Designer and one of my colleague he has some issues.
He is using his pc for audio work and he wants to keep it permanently offline, so he needs to disable all these background services taking up my resources.

His Pc version: Windows 10 Home 1903 build: 18362.1082

He followed some instructions he found from the internet and nothing works.

He ran REGEDIT as an administrator.
Then went to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
Created a DWORD 32bit, named it DisableAntiSpyware
Then he creates a Key inside the Windows Defender folder, named it Real-Time Protection, then put in there the following DWORD 32 bit:

DisableBehaviorMonitoring
DisableOnAccessProtection
DisableScanOnRealtimeEnable

Everything at value 1, hexadecimal base

Then he restarted windows, and indeed Antimalware service wasn’t running anymore, until… he restarted a few times and the pesky thing was there.

He had a look at HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender and the DisableAntiSpyware that I created wasn’t there anymore.

Any suggestion.?
Thanks.